Initial Version of Twig L10N Filters

Adding numeric and currency filters that are aware of locale.

Replacing https://gerrit.wikimedia.org/r/#/c/53653/

Change-Id: I0e1fcd46b2f1caf182ef74c452417d487b3b66dc
Make Thank You Localized!

Use the new L10n filters from twig

Change-Id: I70cc345cb378424a59e49e3018e20c363033782d
Make the Templates Use the new L10n Thing

Change-Id: Iaed4a6e8be492d47137be80e50dda42815f1b9d6