don't run update if it has no values
add couch_group_level parameter
better error handling and minor cleanup
Merge pull request #36 from dimagi/empty_update

don't run update if it has no values
delete data when deleting mapping
Merge pull request #37 from dimagi/group_level

add couch_group_level parameter
Merge pull request #39 from dimagi/clean

better error handling and minor cleanup
Merge pull request #40 from dimagi/clear_delete

delete data when deleting mapping
perfer {} to dict()
Merge branch 'master' into date_range

Conflicts:
	ctable/models.py