cleanup python 3.3 compatibility + added force-bootstrap-library

- Decreased the amount of if/else statements for the Python 3.3 compatiility.

- Added a force-bootstrap-library option for CX_freeze. This prevents appending the library.zip to the bootstrap executable. This is useful when you want to sign your executables with the microsoft signtool (or similair tools).

Tested with Python 3.3