/about: Paginate banned and contibutors.
Delete Userlist.
Delete traffic viewers.
about: Fix /edit and /traffic for logged out users.
UserListing: Skip deleted users.
load_subreddits: Don't load subscriber SRMember.
load_subreddits: Don't load things on SRMember.
Relation._fast_query: Delete TODO message.
Relation._fast_query: Fix data and thing lookups.

Don't retrieve data or thing_data in sgm miss function because that
is used only to lookup and cache (thing1_id, thing2_id, name): rel_id.
Also switch to using _byID_rel so we can actually honor the thing_data
and eager_load kwargs.
_fast_query: Delete unimplemented timestamp_optimize option.
load_subreddits: Don't load 'contributor' SRMembers.

Used for Comment.add_props to see if user can reply to a comment.
That can be looked up if/when it's needed. Also used for
Builder.must_skip to check if the user can view but only if the
Subreddit is private, so also can be looked up when it's needed.
NewController: simplify keep_fn and fix docstring.

Docstring no longer accurately described method's behavior.
Use an intermediate time recording for "build_morechildren".