update behavior for proper cache clearing/hydration

cd40027
- Flush the cache when performing a delete( ) or update( ) call on a Query object

6021217
- Add fetched objects that are fetched from cache to the instance pool, so that PropelObjectCollection::populateRelation() will work correctly when the original object set is fetched from cache.

5250a7d
- Added require statements for dependent classes (for use when not autoloading)