Lazyload jquery.uls library

In the "interlanguage" position ULS is shown after 2 clicks,
so don't load it initially.

In the "personal" position ULS is shown immediately after
the language icon click, so load it, but conditionally.

The new RL module ext.uls.mediawiki is added for setting
jquery.uls defaults in a way that will lazy-load the language names.

Change-Id: Ic33ef034c794a523b5403867196c6098a58eb5b1
Merge "Lazyload jquery.uls library"