Added Python 3 support.

I have added simple Python 3 support.

Nosetests in namecheap_tests.py are passing in 2.7.6, 3.2.3, 3.3.4 and 3.4.1 python versions.

*As a side effect my editor cleaned up some whitespace in code(hope you don't mind:)*
*(I have left tabs as code indentations, i guess you have a good reason for keeping them)*

Please review.