Fix tag filtering on included files and add more debugging

Previously, we were filtering the task list on tags for each host
that was including the file, based on the idea that the variables
had to include the host information. However, the top level task
filtering is play-context only, which should also apply to the
included tasks. Tags cannot and should not be based on hostvars.

lib/ansible/plugins/strategy/__init__.py

@@ -414,6 +414,7 @@ class StrategyBase:
         Loads an included YAML file of tasks, applying the optional set of variables.
         '''
 
+        display.debug("loading included file: %s" % included_file._filename)
         try:
             data = self._loader.load_from_file(included_file._filename)
             if data is None:
@@ -474,6 +475,7 @@ class StrategyBase:
 
         # finally, send the callback and return the list of blocks loaded
         self._tqm.send_callback('v2_playbook_on_include', included_file)
+        display.debug("done processing included file")
         return block_list
 
     def run_handlers(self, iterator, play_context):