Added formatting and line wrapping to checks reference doc.
Removed duplicate "Deprecated in Django A.B" text in docs.

sphinx 1.2+ adds this text itself.
Fixed #22772 -- Defer wizard temporary files deletion.
Fixed #3711, #6734, #12581 -- Bounded connection.queries.

Prevented unlimited memory consumption when running background tasks
with DEBUG=True.

Thanks Rob, Alex, Baptiste, and others.
Fixed #17238 -- Added source code links to docs using sphinx.ext.viewcode.

Thanks santiagobasulto for the suggestion.
Fixed #18314 -- Corrected request.build_absolute_uri() handling of paths starting with //

``HttpRequest.build_absolute_uri()`` now correctly handles paths starting with ``//``.
``WSGIRequest`` now doesn't remove all the leading slashes either,
because ``http://test/server`` and http://test//server`` aren't the same thing
(RFC2396).

Thanks to SmileyChris for the initial patch.
Made a test compatible with Python 2 and 3.
Fixed #17427 -- Removed dubious definition of connections equality.
Fixed test again. Refs #12581.