Use buck rule for ReleaseNotes instead of Makefile

This eliminates the last Makefile in our code base.

Also change the section style within ReleaseNotes from asciidoc style to
asciidoctor style.

Also I feel that put images/link.png under ReleaseNotes and deal with
all the resource packing is too stupid, so I used the unicode emoji
instead of the picture ("🔗"). If this is too crazy, we can also use "#"
instead :) This also affects documentation rendering.

Other side effects:

1. The css of release notes switched from default asciidoc css into
default asciidoctor css.
2. The section anchors for ReleaseNotes/index.html changed from "2_13"
to "s2_13", because asciidoctorj is unhappy with anchors without
letters.

Change-Id: I4adf2ce090385cc6b699445012f10a009892aaac

ReleaseNotes/ReleaseNotes-2.12.txt

@@ -1,5 +1,4 @@
-Release notes for Gerrit 2.12
-=============================
+= Release notes for Gerrit 2.12
 
 
 Gerrit 2.12 is now available:
@@ -7,8 +6,7 @@ Gerrit 2.12 is now available:
 link:https://www.gerritcodereview.com/download/gerrit-2.12.war[
 https://www.gerritcodereview.com/download/gerrit-2.12.war]
 
-Important Notes
----------------
+== Important Notes
 
 *WARNING:* This release contains schema changes.  To upgrade:
 ----
@@ -39,8 +37,7 @@ to change the branch configuration to type `Path` with a pattern like
 `refs/*/master` instead of `Plain` and `master`.
 
 
-Release Highlights
-------------------
+== Release Highlights
 
 This release includes the following new features. See the sections below for
 further details.
@@ -50,11 +47,9 @@ further details.
 * Support for GPG Keys and signed pushes.
 
 
-New Features
-------------
+== New Features
 
-New Change Submission Workflows
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+=== New Change Submission Workflows
 
 * New 'Submit Whole Topic' setting.
 +
@@ -76,8 +71,7 @@ Changes that cannot be submitted due to missing dependencies will no longer
 enter the 'Submitted, Merge Pending' state.
 
 
-GPG Keys and Signed Pushes
-~~~~~~~~~~~~~~~~~~~~~~~~~~
+=== GPG Keys and Signed Pushes
 
 * Signed push can be enabled by setting
 link:https://gerrit-documentation.storage.googleapis.com/Documentation/2.12/config-gerrit.html#receive.enableSignedPush[
@@ -102,8 +96,7 @@ link:https://gerrit-documentation.storage.googleapis.com/Documentation/2.12/conf
 `receive.certNonceSlop`].
 
 
-Secondary Index
-~~~~~~~~~~~~~~~
+=== Secondary Index
 
 * link:http://code.google.com/p/gerrit/issues/detail?id=3333[Issue 3333]:
 Support searching for changes by author and committer.
@@ -141,11 +134,9 @@ Plugins can now temporarily turn on auto-committing in situations where it makes
 sense to enforce all changes to be written to disk ASAP.
 
 
-UI
-~~
+=== UI
 
-General
-^^^^^^^
+==== General
 
 * Edit and diff preferences can be modified from the user preferences screen.
 +
@@ -165,14 +156,12 @@ Plugins may use user-specific URL aliases to replace certain screens for certain
 users.
 
 
-Project Screen
-^^^^^^^^^^^^^^
+==== Project Screen
 
 * New tab to list the project's tags, similar to the branch list.
 
 
-Inline Editor
-^^^^^^^^^^^^^
+==== Inline Editor
 
 * Store and load edit preferences in git.
 +
@@ -187,8 +176,7 @@ Edit preferences are stored and loaded to/from the `All-Users` repository.
 * Add support for Emacs and Vim key maps.
 
 
-Change Screen
-^^^^^^^^^^^^^
+==== Change Screen
 
 * link:http://code.google.com/p/gerrit/issues/detail?id=3318[Issue 3318]:
 Highlight 'Reply' button if there are draft comments on any patch set.
@@ -216,8 +204,7 @@ replying to a change.
 This helps to identify changes when the subject is truncated in the list.
 
 
-Side-By-Side Diff
-^^^^^^^^^^^^^^^^^
+==== Side-By-Side Diff
 
 * link:http://code.google.com/p/gerrit/issues/detail?id=3293[Issue 3293]:
 Add syntax highlighting for Puppet.
@@ -226,40 +213,34 @@ Add syntax highlighting for Puppet.
 Add syntax highlighting for VHDL.
 
 
-Group Screen
-^^^^^^^^^^^^
+==== Group Screen
 
 * link:http://code.google.com/p/gerrit/issues/detail?id=1479[Issue 1479]:
 The group screen now includes an 'Audit Log' panel showing member additions,
 removals, and the user who made the change.
 
 
-API
-~~~
+=== API
 
 Several new APIs are added.
 
-Accounts
-^^^^^^^^
+==== Accounts
 
 * Suggest accounts.
 
-Tags
-^^^^
+==== Tags
 
 * List tags.
 
 * Get tag.
 
 
-REST API
-~~~~~~~~
+=== REST API
 
 New REST API endpoints and new options on existing endpoints.
 
 
-Accounts
-^^^^^^^^
+==== Accounts
 
 * link:https://gerrit-documentation.storage.googleapis.com/Documentation/2.12/rest-api-accounts.html#set-username[
 Set Username]: Set the username of an account.
@@ -276,8 +257,7 @@ the account and the timestamp of when contact information was filed for this
 account.
 
 
-Changes
-^^^^^^^
+==== Changes
 
 * link:https://gerrit-documentation.storage.googleapis.com/Documentation/2.12/rest-api-changes.html#set-review[
 Set Review]: Add an option to omit duplicate comments.
@@ -294,8 +274,7 @@ the same time as the change.
 link:https://gerrit-documentation.storage.googleapis.com/Documentation/2.12/rest-api-changes.html#set-review[
 Set Review]: Add an option to publish draft comments on all revisions.
 
-Config
-^^^^^^
+==== Config
 
 * link:https://gerrit-documentation.storage.googleapis.com/Documentation/2.12/rest-api-config.html#get-info[
 Get Server Info]: Return information about the Gerrit server configuration.
@@ -304,8 +283,7 @@ Get Server Info]: Return information about the Gerrit server configuration.
 Confirm Email]: Confirm that the user owns an email address.
 
 
-Groups
-^^^^^^
+==== Groups
 
 * link:https://gerrit-documentation.storage.googleapis.com/Documentation/2.12/rest-api-groups.html#list-group[
 List Groups]: Add option to suggest groups.
@@ -317,8 +295,7 @@ Get Audit Log]: Get the audit log of a Gerrit internal group, showing member
 additions, removals, and the user who made the change.
 
 
-Projects
-^^^^^^^^
+==== Projects
 
 * link:https://gerrit-documentation.storage.googleapis.com/Documentation/2.12/rest-api-projects.html#run-gc[
 Run GC]: Add `aggressive` option to specify whether or not to run an aggressive
@@ -329,8 +306,7 @@ List Tags]: Support filtering by substring and regex, and pagination with
 `--start` and `--end`.
 
 
-SSH
-~~~
+=== SSH
 
 * Add support for ZLib Compression.
 +
@@ -340,11 +316,9 @@ link:https://gerrit-documentation.storage.googleapis.com/Documentation/2.12/conf
 
 * Add support for hmac-sha2-256 and hmac-sha2-512 as MACs.
 
-Plugins
-~~~~~~~
+=== Plugins
 
-General
-^^^^^^^
+==== General
 
 * Gerrit client can now pass JavaScriptObjects to extension panels.
 
@@ -387,8 +361,7 @@ config will also be updated in this section.
 ** Allow to use GWTORM `Key` classes.
 
 
-Other
-~~~~~
+=== Other
 
 * link:http://code.google.com/p/gerrit/issues/detail?id=3401[Issue 3401]:
 Add option to
@@ -433,8 +406,7 @@ Members of a group with the 'Maintain Server' capability may view caches, tasks,
 and queues, and invoke the index REST API on changes.
 
 
-Bug Fixes
----------
+== Bug Fixes
 
 * link:http://code.google.com/p/gerrit/issues/detail?id=3499[Issue 3499]:
 Fix syntax highlighting of raw string literals in go.
@@ -536,8 +508,7 @@ Changes are now always reloaded from the database during online reindex.
 +
 Under some circumstances it was possible to fail with an IO error.
 
-Documentation Updates
----------------------
+== Documentation Updates
 
 * link:https://code.google.com/p/gerrit/issues/detail?id=412[Issue 412]:
 Update documentation of `commentlink.match` regular expression to clarify
@@ -549,8 +520,7 @@ These endpoints should be considered stable since version 2.11.
 
 * Document that `ldap.groupBase` and `ldap.accountBase` are repeatable.
 
-Upgrades
---------
+== Upgrades
 
 * Upgrade Asciidoctor to 1.5.2