pcb: revision 2

- follow sch in replacing electrolytics with ceramic SMT caps
- move J6 (primary USB KBD connector) left to reduce the proximity of
its pads to the shielding of J8 (PS/2 connector)
- move R9, R10 left to make space for J6
- move BASIC Engine logo down a bit
- update date and revision silkscreen

Author: uli