Update to Glance Contributor's docs

* add mention of Glance contrib guidelines to CONTRIBUTING.rst
* update info about api-ref docs now being in-tree
* add disallowed minor code change doc
  * database scripts, as agreed on at 2016-06-23 meeting
  * non-type-safe changes to tests

Change-Id: I1e997efe72828d99626f5b7f2e2f7c96cae8da98

CONTRIBUTING.rst

@@ -1,7 +1,7 @@
 If you would like to contribute to the development of OpenStack,
 you must follow the steps in documented at:
 
-   http://docs.openstack.org/infra/manual/developers.html#development-workflow
+   http://docs.openstack.org/infra/manual/developers.html#getting-started
 
 Once those steps have been completed, changes to OpenStack
 should be submitted for review via the Gerrit tool, following
@@ -14,3 +14,8 @@ Pull requests submitted through GitHub will be ignored.
 Bugs should be filed on Launchpad, not GitHub:
 
    https://bugs.launchpad.net/glance
+
+Additionally, specific guidelines for contributing to Glance may be found in
+Glance's Documentation:
+
+   http://docs.openstack.org/developer/glance/contributing

doc/source/contributing/documentation.rst

@@ -35,10 +35,23 @@ which you may want to contribute:
 
 * OpenStack API Reference
 
-  There are some Glance-related API quick-reference guides published by the
+  There's a "quick reference" guide to the APIs implemented by Glance:
-  OpenStack Documentation Team. Please see the README in their code repository
+  http://developer.openstack.org/api-ref/image/
-  for more information: https://github.com/openstack/api-site
 
+  The guide is generated from source files in the source code tree under
+  ``api-ref/source``.  Corrections in spelling or typographical errors may be
+  addressed directly by a patch.  If you note a divergence between the API
+  reference and the actual behavior of Glance, please file a bug before
+  submitting a patch.
+
+  Additionally, now that the quick reference guides are being maintained by
+  each project (rather than a central team), you may note divergences in format
+  between the Glance guides and those of other teams.  For example, some
+  projects may have adopted an informative new way to display error codes.  If
+  you notice structural improvements that our API reference is missing, please
+  file a bug.  And, of course, we would also welcome your patch implementing
+  the improvement!
+  
 Release Notes
 -------------
 

doc/source/contributing/index.rst

@@ -13,6 +13,7 @@ Policies
 
    blueprints
    documentation
+   minor-code-changes
 .. bugs
    contributor-onboarding
    core-reviewers

doc/source/contributing/minor-code-changes.rst

@@ -0,0 +1,33 @@
+Disallowed Minor Code Changes
+=============================
+
+There are a few types of code changes that have been proposed recently that
+have been rejected by the Glance team, so we want to point them out and explain
+our reasoning.
+
+If you feel an exception should be made for some particular change, please put
+it on the agenda for the Glance weekly meeting so it can be discussed.
+
+Database migration scripts
+--------------------------
+
+Once a database script has been included in a release, spelling or grammar
+corrections in comments are forbidden unless you are fixing them as a part of
+another stronger bug on the migration script itself.  Modifying migration
+scripts confuses operators and administrators -- we only want them to notice
+serious problems.  Their preference must take precedence over fixing spell
+errors.
+
+Tests
+-----
+
+Occasionally someone proposes a patch that converts instances of
+``assertEqual(True, whatever)`` to ``assertTrue(whatever)``, or instances of
+``asertEqual(False, w)`` to ``assertFalse(w)`` in tests.  Note that these are
+not type safe changes and they weaken the tests.  (See the Python ``unittest``
+docs for details.)  We tend to be very conservative about our tests and don't
+like weakening changes.
+
+We're not saying that such changes can never be made, we're just saying that
+each change must be accompanied by an explanation of why the weaker test is
+adequate for what's being tested.