1229 jr 41767005 find by multiple ids

Lots of good stuff in this branch!

1) Moved paging to PyFacebook.get( ) as a param, default False

2) Cleaned up find_by_adaccount_id, added this method for AdCampaign and AdCreative

3) Added find_by_ids method to AdGroup, AdCampaign and AdCreative

4) Cleaned up some documentation and other housekeeping, just a touch of class if you will