move hostvars.vars to vars

this fixes duplication under hostvars and exposes all vars in the vars dict
which makes dynamic reference possible on 'non hostvars'

lib/ansible/vars/__init__.py

@@ -259,8 +259,6 @@ class VariableManager:
             except KeyError:
                 pass
 
-        all_vars['vars'] = all_vars.copy()
-
         if play:
             all_vars = combine_vars(all_vars, play.get_vars())
 
@@ -343,6 +341,8 @@ class VariableManager:
             all_vars['ansible_delegated_vars'] = self._get_delegated_vars(loader, play, task, all_vars)
 
         #VARIABLE_CACHE[cache_entry] = all_vars
+        if task or play:
+            all_vars['vars'] = all_vars.copy()
 
         debug("done with get_vars()")
         return all_vars