Major changes to ORM

 * Restructed relationship definitions
 * count_all now works with conditions
 * Call reset(FALSE) before count_all() to continue querying to grab
results
 * Got rid of HABTM (use has_many "through")
 * Aliasing support for has_many relationships
 * Updated with() for use with new Database
 * Improved performance (hopefully!)
 * as_array() now includes one-one models that were already loaded
 * Got rid of ORM_Iterator
 * Added support for database casting, i.e.
DB::select('*')->from('user')->as_object('Model_User')->execute()
 * More!