resourceloader: Ensure 'user' loads after 'site' (asynchronously)
Regression from
19a40cd3ad which made the 'site' module load asynchronously,
but the 'user' module was still loaded synchronously which meant it ran before
the site module finished.
Full test script at <https://gist.github.com/Krinkle/
5db1d237da241b243485>.
Also:
* This changes the 'user' module to load asynchronously.
* Similar to
19a40cd3ad for site module, this makes the styles for the user
module load twice. Harmless but doesn't look pretty internally.
* Remove the obsolete XXX-comment from
0b5389d98d (r56770).
* Add comment documenting the fact that the 'excludepages' feature can cause
User/common.js and User/vector.js to be mis-ordered when the user previews
common.js edits. This has always been the case (since 2009) and is merely
being documented here.
Bug: T32358
Bug: T106736
Bug: T102077
Change-Id: Id599b6be42613529fb7f4dd3273f36ccadb3a09e