ropemode is unusable with unicode

source files are with encoding: utf8

most docstrings contains utf and specified like u"""юникод"""

emacs command rope-move-current-module -- review fails:

```
  File "/usr/lib/python2.7/dist-packages/ropemode/refactor.py", line 48, in show
    diffs = str(changes.get_description())
UnicodeEncodeError: 'ascii' codec can't encode characters in position 1669-1682: ordinal not in range(128)
```
