[pycrypto] Once again: Python3 with PyCrypto

[Thorsten Behrens]

Replying to myself, pathetic ...

I thought about the question of helper functions some more while 
repairing the snow-blower. I am going to use helpers, not redefine 
existing functions, because:

- No potential for shooting self in foot
- Code becomes self-documenting as far as text/data strings go. It'll be 
blatantly obvious what is a text string (expected result, for example), 
and what is data string (byte string)
- Easier to maintain. No "why's there an ord() there? Why's it behave 
like that? Huh?!?"

Nothing to see here, move along :).

Thorsten