Update requirements for Django 1.5/Django CMS 2.4

Update the pip requirements file to reflect the required packages
for Django 1.5.* and Django CMS 2.4.*

Also, remove entries in the requirements file for packages that
are not directly required by this software.  They should get
installed automatically by pip when the explicitely named
dependencies are installed.

Remove the pip requirements file for Django 1.3 as we're no longer
supporting this version

Addresses #660
Update language handling for Django CMS 2.4

Django CMS >= 2.4 stops using ``cms.middleware.multilingual.MultilingualURLMiddleware``
in favor of ``django.middleware.locale.LocaleMiddleware`` so update
the middleware settings accordingly.  ``LocalMiddleWare`` also requires
identifying language-aware patterns using ``i18n_patterns``.
See http://docs.django-cms.org/en/latest/upgrade/2.4.html#removed-the-multilingualmiddleware

In order to use ``i18n_patterns`` with the storybase app URLs, include
them using ``include`` instead of importing and concatenating them to
``urlpatterns``.

Add ``cms.middleware.language.LanguageCookieMiddleware`` to middleware
See http://docs.django-cms.org/en/latest/upgrade/2.4.html#added-languagecookiemiddleware

Addresses #660
Remove simple_language_changer

This was deprecated in Django CMS 2.4

See http://docs.django-cms.org/en/latest/upgrade/2.4.html#pending-deprecations

Addresses #660
Switch to "new-style" url tag

Starting with Django 1.5, an unquoted url name like::

    {% url myview %}

won't work ("myview" is interpretted as a variable name)
and needs to be changed to::

    {% url "myview" %}

Addresses #660
Mock as_view when testing view class methods

Mock the ``as_view()`` method of a class-based view when
unit testing methods of a view class in order to properly
bind the view arguments and keyword arguments.

See http://tech.novapost.fr/django-unit-test-your-views-en.html
Merge branch 'develop' into 660-django_1.5_support

Pull in mocking of ``as_view()`` method of class-based views.