Refactor to action controller subclasses. Tweak modcenter.

Signed-off-by: Norv <a.w.norv@gmail.com>
Rework createList() callbacks in moderation center controller:
instance methods for the list, and database-working functions
for the db work involved. Wip cleaning globals from subs (tweaks
should be in list_() methods.)

Signed-off-by: Norv <a.w.norv@gmail.com>