New USE_MODELTRANSLATION setting that adds "modeltranslation" to the optional apps, available in templates and set to false if the module couldn't be loaded. Examples of configuration pieces needed for multilingual projects (i18n and languages settings, i18n context processor, locale middleware and i18n patterns).
Register all Mezzanine content for translation (excluding keywords as they will need special handling due to generics).
Base classes need to be registered for translation before their descendants.
Update all translations of derived / generated fields when models are saved (Slugged.slug, MetaData.description and Page.titles).
Let TranslationAdmin be used for anything that potentially can have translated fields. Use modeltranslation script to display translation fields as tabs (including a base jQuery UI theme style from: http://code.jquery.com/ui/1.9.1/themes/base/jquery-ui.css).
Avoid inserting translation fields into forms as extra fields, TranslationAdmin handles them properly on its own.
New ``update_generated_fields`` command (currently resaving all models deriving from Slugged, MetaData and Page).
In case of some fields (such as "slug"), one cannot have one translation set and rely on fallbacks for other languages, as they don't work with filtering / lookups.
For example, if you create a new project loading example fixtures, sync and update translation fields, you still won't be able to browse most pages in any non-default language until you give them a chance to generate translated slugs.
Merge branch 'feature/modeltranslation-integration' into develop

Conflicts:
	mezzanine/project_template/settings.py
	mezzanine/project_template/urls.py