Added a class for handling ItemEditorForms with filter_horizontal fields
Mergered multiple form classes into FormWithAdminFeatures class. Added deprication warning to FormWithRawIDField class.
Stripped repetitive code from FormWithRawIDFields by inheriting from FormWithAdminFeatures
Fixed case where class/instance variables don't exist in FormWithAdminFeatures
Merge pull request #3 from jonhuber/master

FormWithAdminFeatures