Add defaults(), find_key(), find_last_key(), for_in(), functions(), has() and is_<type>()
Use iteritems and setdefault
find_key() = find_last_key()
Change type to isinstance
Only import functions_
isinstance() instead of type()
One liner
Merge pull request #19 from nathancahill/functions

Add defaults(), find_key(), find_last_key(), for_in(), functions(), ...