Don't send UDFC data when perm not there
Update UDF documentation/debug output
Change the way collection udfs save

Only cast to python when you are instantiating objects, not saving. save_with_user was calling collection_fields() which cleans values and casts to python. These can't save properly.

Don't save collection udfs when they haven't changed. This is important for permissions, since UDFModels call this method on every save, even saves by users that aren't permitted to change UDF values.
Merge pull request #1233 from steventlamb/bug/collection_udf_ui_perms

Bug/collection udf ui perms