pure python blowfish cleanup

[clach04]

Current import logic can end up importing python2 only blowfish implementation under Python3.
Quickest thing would be to do conditional import based on version.

Also look at https://www.seanet.com/~bugbee/crypto/blowfish/.

[clach04]

Taken care of in:

• 319b9fe
• 34b6f5a

worth looking at alternative Blowfish (bugbee) implementations

[clach04]

blowfish.py should run under any version of Python2.
(Versions 2.4 and earlier remain untested however.)

blowfish.py3 runs under Python 3.2 and is backward
compatible to 2.6 and 2.7.

Both versions also run under pypy 1.5 (2.7.1).

...

of Blowfish that was subsequently enhanced by Ivan Voras.
Use Google to find them. Because both implementations are
governed by the GPL, I was motivated to create a version
with fewer encumberances. Thus...

Copyright (c) 2011 by Larry Bugbee, Kent, WA, USA
ALL RIGHTS RESERVED.

blowfish.py IS EXPERIMENTAL SOFTWARE FOR EDUCATIONAL
PURPOSES ONLY. IT IS MADE AVAILABLE "AS-IS" WITHOUT
WARRANTY OR GUARANTEE OF ANY KIND. USE SIGNIFIES
ACCEPTANCE OF ALL RISK.

To make your learning and experimentation less cumbersome,
blowfish.py is free for any use. Feel free to extend,
modify, and experiment. I choose, however, to retain my
copyrights.

Enjoy,

Larry Bugbee
April 2011