add python 3 support

README is updated to python 3
these changes need to work for both python 2 and 3.  This will break for python < 3:

```
python
Python 2.7.6 (default, Apr  9 2014, 11:48:52)
[GCC 4.2.1 Compatible Apple LLVM 5.1 (clang-503.0.38)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> from urllib import parse
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: cannot import name parse
>>> import urllib.parse
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: No module named parse
```