Get rid of debugging prints
Improve error message
Don't read or write from a terminal
Let ungeli do its own computation of the keys

C's pkcs5v2 is much faster than Python (even a naive implementation)
and it stops the need to pass around keys on the commandline which is
good for a feeling of security.
Include the password which geli-test is encrypted with
Update README to reflect that Python is not needed now
Remove unneeded file

I don't think there's anything left in this which is of particular
interest...
Enable compiler optimization