Added comments and deleted dead code
Implemented EntityBuilder and EntityCache classes, to allow us to
hold on to entities built in the course of performing a fetch.  This gives us
performance gains, and also lets us short circuit any circular references.

Started refactoring ORMDataSource, to pull out supporting code

Fixed leaked cursor issue in SQLiteDialect
Merge branch 'master' of github.com:theJenix/ormada