add in a reason for invalid receipts (bug 756297)
Merge pull request #1124 from andymckay/756297

add in a reason for invalid receipts (bug 756297)
Refactored AllowAppOwner a bit to remove the reviewer check (bug 915791)

This removes the dependency on a Tastypie authorization class.
show time and IP address of last login for AMO users (bug 690284)