rename non-cycling imports to 'from jedi import ..'

jedi/refactoring.py

@@ -15,10 +15,10 @@ following functions (sometimes bug-prone):
 
 from __future__ import with_statement
 
-import modules
-import difflib
-import helpers
-import parsing_representation as pr
+from jedi import modules
+from jedi import difflib
+from jedi import helpers
+from jedi import parsing_representation as pr
 
 
 class Refactoring(object):