Fix for issue #38: Python 3.3: unable to locate initialization module

The bootstrap EXE didn't work anymore when using Python 3.3.

Simply creating a check for Python 3.3 and adding the source size to the struckt.pack solves this.
We can safely set the source size to zero since Python doesn't check the actual size yet.

Changes are tested with Python 3.3 32-bit on Windows 8 Pro.

By the way, most of the credits go to Anthony_tuininga on bitbucket, he inspired me to implement this. ;)
https://bitbucket.org/anthony_tuininga/cx_freeze/commits/032baa5a5d0e19b2bef801cf72d040752d9d7040