Docs: Remove ambiguity.

The docs to the LANGUAGES setting were using both the term language code
and language name for the same thing.
Updated bios of committers
Merge pull request #956 from maikhoepfel/master

Removed ambiguity regarding LANGUAGES setting
Improved FormView docs in class-based views index.

Thanks Stefan Berder.
Fix #20158: invalid code in queryset_pickle test models.
Merge pull request #975 from bmispelon/ticket-20158

Fix #20158: invalid code in queryset_pickle test models.
Fixed #14540 -- Added Porto-Rico specific formats

Thanks rosarior for the report and the file proposal.
Fixed #20159 -- Mispelled attribute in multi-db documentation example.

Thanks to sane4ka.sh at gmail for the report!
Fixed #20160 -- Erronous reference to `module_name` in admin doc.

Ref #19689.
Fixed #20150 -- Fixed an error in manager doc example
Fixed setup.py overlaid-install warning.

Before this change, if you had a global Django installation in /usr/local/, you
might get a spurious warning when installing Django within a virtualenv.

Thanks epicserve for the report and debugging help.
Merge pull request #977 from nims11/ticket_20150

Fixed #20150 -- Fixed an error in manager doc example
Fixed #15379 - Added "how to cite Django" to FAQ.

Thanks Russ and Susan Tan.
Fixed #19582 - Added a static files tutorial.

Thanks James Pic.
Fixed #19897 - Updated static files howto.

Thanks Jan Murre, Reinout van Rees and Wim Feijen,
plus Remco Wendt for reviewing.
Fixed #19998 -- Fixed --ignorenonexistent support for XML based fixtures.
Fixed #20130 -- Regression in {% cache %} template tag.
Fixed #20059 -- Updated humanize tests to force 'en' language setting.
Remove unnecessary if conditions

if obj it None, it's None, there's no need to check it
Merge pull request #963 from richardcornish/master

Updated bios of committers