Register ResourceLoader modules the conventional way

* Remove $moduleInfo trick; it's an expensive way to save typing a few
  characters. (If you are really keen to save those characters, consider
  flattening the file hierarchy: does every mmv module have to have 'mmv' both
  in its directory name *and* in the filename itself?)
* Using an anonymous, immediate function to create a scope and thereby avoid
  polluting global scope is a JavaScript pattern that doesn't translate well to
  PHP. The idiomatic way of doing that in PHP is to use namespaces. But you
  don't even need to do that, since all the variables you are manipulating are
  global anyway, now that $moduleInfo is gone.
* Use the same pattern as VisualEditor for registering multiple modules in
  bulk.
* Always put extension info under 'other' section. If a value is configurable,
  then it is not essential / inherent to the extension itself. The fact that
  the extension is a beta feature is a property of the way it is deployed on
  the Wikimedia cluster; it's not descriptive of the extension in itself. (I
  would argue getting rid of the 'betafeatures' section everywhere for this
  reason.)

Change-Id: Ifc0a05362db990e4c073761a00ba17326c5ebbdb