Add a REST API endpoint for getting project configuration

To start, only expose the inheritable booleans stored in the project
config, and only to users who can see refs/meta/config.

Change-Id: I299a5317fb641e84b899f8240764c4902a34c72a

Documentation/rest-api-projects.txt

@@ -408,6 +408,41 @@ link:#repository-statistics-info[RepositoryStatisticsInfo] entity.
   }
 ----
 
+[[get-config]]
+Get Config
+~~~~~~~~~~
+[verse]
+'GET /projects/link:#project-name[\{project-name\}]/config'
+
+Gets some configuration information about a project. Note that this
+config info is not simply the contents of `project.config`; it generally
+contains fields that may have been inherited from parent projects.
+
+.Request
+----
+  GET /projects/myproject/config
+----
+
+A link:#config-info[ConfigInfo] entity is returned that describes the
+project configuration. Some fields are only visible to users that have
+read access to `refs/meta/config`.
+
+.Response
+----
+  HTTP/1.1 200 OK
+  Content-Disposition: attachment
+  Content-Type: application/json;charset=UTF-8
+
+  )]}'
+  {
+    "kind": "gerritcodereview#project_config",
+    "use_contributor_agreements": false,
+    "use_content_merge": true,
+    "use_signed_off_by": false,
+    "require_change_id": true
+  }
+----
+
 [[run-gc]]
 Run GC
 ~~~~~~
@@ -896,6 +931,35 @@ statistics of a Git repository.
 |`size_of_packed_objects`  |Size of packed objects in bytes.
 |======================================
 
+[[config-info]]
+ConfigInfo
+~~~~~~~~~~
+The `ConfigInfo` entity contains information about the effective project
+configuration.
+
+Fields marked with * are only visible to users who have read access to
+`refs/meta/config`.
+
+[options="header",width="50%",cols="1,6"]
+|======================================
+|Field Name                   |Description
+|`use_contributor_agreements*`|
+If set, authors must complete a contributor agreement on the site
+before pushing any commits or changes to this project.
+|`use_content_merge*`|
+If set, Gerrit will try to perform a 3-way merge of text file content
+when a file has been modified by both the destination branch and the
+change being submitted. This option only takes effect if submit type is
+not FAST_FORWARD_ONLY.
+|`use_signed_off_by*`|
+If set, each change must contain a Signed-off-by line from either the
+author or the uploader in the commit message.
+|`require_change_id*`|
+If set, require a valid link:user-changeid.html[Change-Id] footer in any
+commit uploaded for review. This does not apply to commits pushed
+directly to a branch or tag.
+|======================================
+
 
 GERRIT
 ------