Fixed discovery of the Django installation during tests.

If Django was symlinked into site-packages the previous approach to discover
the tests subdirectory would fail. The revised version now always points to
the location of the source and not the import path.
Fixed #19922 - Typo in translation docs.

Thanks amoebob for the report.
Added note about updating default docs version in howto-release doc.
Merged core translations from 1.5 branch
Merged contrib translations from 1.5 branch
Fixed i18n test to match changed translation

Forward port of ab6ff2e0ac from stable/1.5
[py3] str.decode does not exist; str.encode was intended
Added a note about creating new doc versions; update stable doc version before announcement.
Added Python 3.2/3.3 trove classifiers in setup.py
Don't use os.system() in compilemessages.

Fixes #19584.

This implies stop storing file path command line arguments in envvars as
a security measure to start relying on with Popen's shell=False instead,
and addition of an 'utils' module.

Thanks kmichel_wgs for the report.
Move management helper function to new utils module.

This allows us to iremove an inter-command import.
Simplified compilemessages tests a bit.
Removed a .mo file incorrectly put under Git control.
[py3] Always fed hashlib with bytes.
Fixed #16807 - Added a class-based views intro.

Thanks Preston Holmes for the text.
Fixed #19861 -- Transaction ._dirty flag improvement

There were a couple of errors in ._dirty flag handling:
  * It started as None, but was never reset to None.
  * The _dirty flag was sometimes used to indicate if the connection
    was inside transaction management, but this was not done
    consistently. This also meant the flag had three separate values.
  * The None value had a special meaning, causing for example inability
    to commit() on new connection unless enter/leave tx management was
    done.
  * The _dirty was tracking "connection in transaction" state, but only
    in managed transactions.
  * Some tests never reset the transaction state of the used connection.
  * And some additional less important changes.

This commit has some potential for regressions, but as the above list
shows, the current situation isn't perfect either.
Refactored database exceptions wrapping.

Squashed commit of the following:

commit 2181d833ed1a2e422494738dcef311164c4e097e
Author: Aymeric Augustin <aymeric.augustin@m4x.org>
Date:   Wed Feb 27 14:28:39 2013 +0100

    Fixed #15901 -- Wrapped all PEP-249 exceptions.

commit 5476a5d93c19aa2f928c497d39ce6e33f52694e2
Author: Aymeric Augustin <aymeric.augustin@m4x.org>
Date:   Tue Feb 26 17:26:52 2013 +0100

    Added PEP 3134 exception chaining.

    Thanks Jacob Kaplan-Moss for the suggestion.

commit 9365fad0a650328002fb424457d675a273c95802
Author: Aymeric Augustin <aymeric.augustin@m4x.org>
Date:   Tue Feb 26 17:13:49 2013 +0100

    Improved API for wrapping database errors.

    Thanks Alex Gaynor for the proposal.

commit 1b463b765f2826f73a8d9266795cd5da4f8d5e9e
Author: Aymeric Augustin <aymeric.augustin@m4x.org>
Date:   Tue Feb 26 15:00:39 2013 +0100

    Removed redundant exception wrapping.

    This is now taken care of by the cursor wrapper.

commit 524bc7345a724bf526bdd2dd1bcf5ede67d6bb5c
Author: Aymeric Augustin <aymeric.augustin@m4x.org>
Date:   Tue Feb 26 14:55:10 2013 +0100

    Wrapped database exceptions in the base backend.

    This covers the most common PEP-249 APIs:
    - Connection APIs: close(), commit(), rollback(), cursor()
    - Cursor APIs: callproc(), close(), execute(), executemany(),
      fetchone(), fetchmany(), fetchall(), nextset().

    Fixed #19920.

commit a66746bb5f0839f35543222787fce3b6a0d0a3ea
Author: Aymeric Augustin <aymeric.augustin@m4x.org>
Date:   Tue Feb 26 14:53:34 2013 +0100

    Added a wrap_database_exception context manager and decorator.

    It re-throws backend-specific exceptions using Django's common wrappers.
Fixed two bugs in 59a35208.

* StandardError doesn't exist any more under Python 3.
* Python 2.6 still allows `raise "foo"`.
Fixed a PendingDeprecationWarning in template_tests.
Fixed a test that relied on database exceptions not being wrapped.