Load most of TMH and its dependencies on demand

This removes 17kb of compressed content from every article pageload.

Change-Id: I43af3c87a2db733f280b42d4083f18252f49cae0
Mingle: https://wikimedia.mingle.thoughtworks.com/projects/multimedia/cards/543
Bug: 55550
Merge "Load most of TMH and its dependencies on demand"