Docs: Improve releasing notes
Docs: various cleanups doing release preperation
Translations: update from Pootle.locamotion.org
Docs: 2.5.1-rc1 release notes and related changes
Adjust minimum versions for required software

- Update minimum versions on requirements/*.txt
- Do the same in depcheck.py code
- Generate updated minimum requirements files (Still not sure why we have
  these)
Bump version to 2.5.1-rc1
Docs: adjust INSTALL to reflect 2.5.1 behaviour
Docs: typo
Docs: turn these into local refs not full URLs
Docs: typo
Requirements: min and pinned are generated files.

Clarify that minimum and pinned requirements are generated files.

I think I finally understand the need for these files - sorry Alex

- min-requirements.txt - these are the minimum versions in requirements/*.txt.
  Call this the minimum that we contractually agree will work.
- requirements.txt - or the pinned version.  Pinned because at some time in
  space we pinned it to these versions.  Essentially these are the maximum
  versions that were available at the time of release.  After we release
  versions will increase and their is a risk that a neweer version won't work
  with Pootle.  The pinned requirements is the contractual maximum that should
  work.

What is missing is that we don't actively test against these versions.
Cleanups: Remove latest references to old wiki
Drop django-registration app from Pootle codebase

Seems that the code was not on Pootle codebase because it was necessary to
localize it, but perhaps because this way was easier to release Pootle.

The new registration app doesn't save the RegistrationForm, so we can't
rely on it for saving the agreements accepted when the user registered.

Use pinned version for the package in requirements to avoid ugly surprises.

Fixes bug #2579
Drop django-contact-form from Pootle codebase

Since this app was kept for localization a custom app that extends
django-contact-form was put in place just to keep the form localized.

Aligned with Evernote's approach as much as possible while keeping it simple.

Use pinned version for the package in requirements to avoid ugly surprises.

Fixes bug #3139
Profiles: Apply PR to get rid of function-based generic views

The PR is in https://bitbucket.org/ubernostrum/django-profiles/pull-request/6/

There is another PR with a slightly different approach, but when and if
django-profiles finally supports class-based generic views the code will be
quite similar to any of these two PRs.

Whitespace changes are not merged to make it easier to see the real changes.

This commit and the previous two ones fix bug #2517
Bump required Django version to 1.5.5
Update Travis config to test latest Django releases
Refactor manage.py to avoid deprecation errors

execute_manager() was deprecated on Django 1.5 and removed in 1.6.
Use json library instead of simplejson bundled with Django

simplejson will be no longer bundled with Django. Django 1.6 throws warnings,
and we don't rely on Python 2.5 anymore so we can use the json library which
is provided by newer Python versions.
Set default ALLOWED_HOSTS in settings

This allows to use runserver in Travis tests on Django 1.6.