added simple requirements.txt
Initial python3k porting

The unit tests work for both python 2.7 and python 3.3. Problem is, the use
case defined in the README is not working properly... Although, it isn't
working either in the main branch.
fixed README.md indentation
Merge and improve remote-tracking branch 'jaormx/master'

Conflicts:
	tests/tests.py
	tpb/tpb.py