Add "rename in superclass" and "replace in strings" option to rename

Rope supports renaming methods and members in the complete hierarchy.

For example, in the following

  class A(object):
    def foo(self): pass

  class A2(A):
    def foo(self): pass

We want to be able to rename A2's foo as well as A's foo at the same
time.

Rope supports this as "in_hierarchy" so add it to the rename dialog.

Also, rope allows to change occurences in strings and docstrings, let
the user choose whether he wants that as well.