Fix loops and memory model of the Brainfuck interpreter.
Fix loops and memory model of the Brainfuck interpreter.

Loops should now be working properly.

The interpreter now uses a conceptually infinite array.
Moving to the left from position 0 does nothing.
Increment and decrement now wraps in the inclusive range [0-255] instead of panicking.

Closes #2.

nbp/holyjit,nbp/holyjit