Clean up, fix errors on demos.
Clean up, fix errors on demos.

* Fix 404 error for ve.ui.Icons-{raster,vector}.css
  Follows-up 9563f08 / I840f72426f9a.

makeStaticLoader.php:
* Clean up old code.
* Error out early for missing module.
* Put i18n stuff in the right place
  (some modules access ve.msg from the global scope to
  assign status variables, for standalone on demos this was
  failing due to wrong load order)

Change-Id: Idbff4c5136d567da747d9ae373cd2f6c3ee7fb1c

wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui