Initial commit of first four (!) PCB revs.

1.0) Never saw production, unfinished.

2.0) Fabbed, but holes for ZIF sockets & many other components far too
small. What I get for not measuring. :P

3.0) Holes enlarged, relayout, etc. Works kinda, but clock stuff is
completely bogus since I added a motherfuckton of parasitic
capacitance/inductance with all those traces. If your chip expects a
clock signal after reset, it ain't getting it.

4.0) Latest version.
  * Eliminates 20 pin socket (have yet to use an ATTiny 2314 or 4313)
  * Drops clock signal from all ATTiny's,
  * Remove 3.3V support since basically all Atmel's chips I'm working
    with can handle the entire voltage range. Should re-add for external
    programming support, but not a big deal for now.
  * Added target reset button
  * Moved LED status indicators from D7-9 to D2-4 for easier layout.
    This means the firmware will have to be changed!
initial firmware checkin with minor tweaks from the arduino dist to get it to compile and eliminate some errors
changing pin defs for rev4 board