Un-bloat and speed-up (FYI, not for merge)

Hi,
I *really* like your idea (thanks for your awesome work!), but I think that 2458 lines of code is a tad on the enterprise side of things and I could not stand the slowness of everything. I rewrote the whole thing, re-implementing everything (or so I hope) except for the tty pony stuff and cleaned up the repo a bit for my personal use.
I changed the command line options towards a more standard usage and added a "--center" option horizontally centering the pony on the terminal.
The new script is 117 lines long and about 50-85% faster (now limited by the startup time of the python interpreter). Especially -q (random pony with quote) is now usable for me for login shells etc.
Missing stuff:
-----------------
 * doc
 * tty ponies

You may want to consider using my code, though you would have to fix these things (and probably some more which I forgot).