Added some function links in translation docs

    ``override`` is also usable as a function decorator.

.. function:: check_for_language(lang_code)

    Checks whether there is a global language file for the given language

    code (e.g. 'fr', 'pt_BR'). This is used to decide whether a user-provided

    language is available.

.. function:: get_language()

    Returns the currently selected language code. Returns ``None`` if

Calling this function with the value 'de' will give you ``"Willkommen"``,

regardless of :setting:`LANGUAGE_CODE` and language set by middleware.

Functions of particular interest are ``django.utils.translation.get_language()``

which returns the language used in the current thread,

``django.utils.translation.activate()`` which activates a translation catalog

for the current thread, and ``django.utils.translation.check_for_language()``

Functions of particular interest are

:func:`django.utils.translation.get_language()` which returns the language used

in the current thread, :func:`django.utils.translation.activate()` which

activates a translation catalog for the current thread, and

:func:`django.utils.translation.check_for_language()`

which checks if the given language is supported by Django.

To help write more concise code, there is also a context manager

``django.utils.translation.override()`` that stores the current language on

:func:`django.utils.translation.override()` that stores the current language on

enter and restores it on exit. With it, the above example becomes::

    from django.utils import translation