There are lots of cases where we can inject a User object without
additional efforts. Now $wgUser is only used inside AFComputedVariable,
which is a little bit harder to handle because some instances of that
class are serialized in the DB, and thus we cannot easily change the
constructor until T213006 is resolved.
This partly copies what Ia474f02dfeee8c7d067ee7e555c08cbfef08f6a6 tried
to do, but adopting a different approach for various can*() methods:
they're now static methods in the AbuseFilter class, so future callers
don't need to instantiate an AbuseFilterView class. This also allows to
re-use those methods in an API module for editing filters (T213037).
Bug: T213037
Bug: T159299
Change-Id: I22743557e162fd23b3b4e52951a649d8c21109c8
Follow-up of Iaca492371f48fecf543268c179a651841ed12c3f. This patch adds
the new module, plus some technical changes to private details-related
methods and globals.
Bug: T210329
Depends-On: I613dbadb8f75c8c4116a362607563a436a73d321
Change-Id: I3c45b74c36c191083df184ed57416067a75f6591
