0.4

Program:
- Bagman support (wrong colors)

- Early Wizard of Wor support (not playable).

- New experimental AY-3-8910 sound emulation code provided by Andy Milne
  (andy@canetics.com). This sounds better in some places and worse in others.
  It is used by Crazy Climber, Crazy Kong and Bagman. Let me know what you
  think.

Source:
- Optimizations in drawgfx(), Mr. Do!'s title screen and intermissions now
  run faster, Crazy Climber and Crazy Kong benefit as well.

- Use version 1.1 of Z80Em by Marcel de Kogel. Faster!
  (note that I had to make a couple of changes to Z80.c to make Crazy
  Climber work).

- Handle IN and OUT instructions in the same way as memory accesses (table
  of handler functions). The parameters of the functions are the same, so
  the same function can be used both for memory and ports.
  Had to change the driver structure, removed the pointers to _in and _out
  functions and added port_read and port_write array pointers.
  Also defined a generic interrupt_vector_w() function, this makes the Pac
  Man driver tinier (look at pacman/machine.c, it's now there only to handle
  the cheat).