Cleanup static analysis errors

Cleanup static analysis errors

While prepping the code base for using etsy/phan i found a few problems.
A couple are real problems, while others are just places etsy couldn't
figure out the types.

* AuthPlugin referenced UserLoginTemplate which doesn't exist. Tracing
  back usages this accepts classes that extend from BaseTemplate.
* DatabaseSqlite had an invalid @var annotation.
* LoadBalancer had some missing or under-defined annotations. Make them
  more specific where possible.
* SqlBagOStuff didn't have the appropriate use statement for
  WaitConditionLoop and probably doesn't work. Also updated annotations
  that point to non-existent DatabaseBase to use IDatabase.

Change-Id: Iff2270b418ad2f8f97cfdb6df646c435d3283536