Minor edits.
Implemented support for cProfile-based profiling in the driver code.

Might be useful, I really feel there *must* be room for optimization here.
Various random attempts at micro-optimization.

- Turn input to bytearray, so we don't have to call ord().
- Simplified an expression or two.
- Use str() constructor to turn output bytearray back to string.

Of course, all of these obvious improvements have no effect I've been able to measure. Pretty much.

Low-hanging fruit of lzjb, where art thou?