modularization of inventory_import command

This separates file parsing logic that was mixed
in with other important code inside of the
inventory import command.

The logic around MemObject data structures was
moved to utils, and the file parsing was moved
to a legacy module. As of this commit, that
module can operate within the Tower environment
but it will be removed.

Also refactor the loggers to fix old bug and
work inside of the different contexts - the
Loader classes, mem objects, and hopefully
the inventory modules eventually.

awx/api/serializers.py

@@ -1458,7 +1458,7 @@ class InventorySourceOptionsSerializer(BaseSerializer):
     class Meta:
         fields = ('*', 'source', 'source_path', 'source_script', 'source_vars', 'credential',
                   'source_regions', 'instance_filters', 'group_by', 'overwrite', 'overwrite_vars',
-                  'timeout')
+                  'timeout', 'verbosity')
 
     def get_related(self, obj):
         res = super(InventorySourceOptionsSerializer, self).get_related(obj)