move existing content into the new standard structure

This patch rearranges and reformats existing content.

It replaces the home-grown autodoc feature with the one built into pbr,
for consistency with other OpenStack projects.

It depends on the doc-migration spec and a pbr feature to allow us to
specify where the autodoc content should go in the source tree during
the build.

Change-Id: I8d2bb11b5ef3e46fcd22c8bed8f84060d8ab6f03
Depends-On: Ia750cb049c0f53a234ea70ce1f2bbbb7a2aa9454
Depends-On: I2bd5652bb59cbd9c939931ba2e7db1b37d2b30bb
Signed-off-by: Doug Hellmann <doug@doughellmann.com>

setup.cfg

@@ -36,7 +36,6 @@ console_scripts =
 [build_sphinx]
 builders = html,man
 all-files = 1
-warning-is-error = 1
 source-dir = doc/source
 build-dir = doc/build
 
@@ -45,3 +44,9 @@ upload-dir = doc/build/html
 
 [wheel]
 universal = 1
+
+[pbr]
+autodoc_index_modules = True
+autodoc_exclude_modules =
+  glanceclient.tests.*
+api_doc_dir = reference/api