WIP/unicode everywhere

Unlike python3, python2 standard library modules operates with bytes objects.
Mixin unicode and bytes in python2 can be trouble. Example:
```
>>> import os
>>> os.path.join('/tmp', 'ж')
'/tmp/\xd0\xb6'
>>> os.path.join('/tmp', u'ж')
u'/tmp/\u0436'
>>> os.path.join(u'/tmp', u'ж')
u'/tmp/\u0436'
>>> os.path.join(u'/tmp', 'ж')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python2.7/posixpath.py", line 80, in join
    path += '/' + b
UnicodeDecodeError: 'ascii' codec can't decode byte 0xd0 in position 1: ordinal not in range(128)
```
and another example:
https://github.com/timothycrosley/frosted/issues/10

The solution may be to wrap all functions in standart library that interact with operating system or operate with strings. Candidates: os, os.path, tempfile, glob, fnmatch, shutil, subprocess...

Is that way interesting for pies?