pentium: Some stuff to make lindbergh go further [O. Galibert]
small cleanup
upd7810: use intermediate flip flops for extended timer/event counter

The extended timer/event counter uses intermediate flip flops (LV0 and
LV1) before writing the output to CO0 and CO1.

The introduction of LV0/LV1 addresses three issues:
- Level inversion occurs after the flip flop is output, not before;
- The intermediate flip flop can be altered without affecting the
  output of CO0/CO1;
- upd7810_write_EOM() didn't work properly when the level inversion
  bit was set along other bits.
steppers: add absolute position
peplus.c: Documentation update - NW
peplus.c: Slight update - NW
Merge pull request #43 from ramiropolla/upd7810

upd7810: use intermediate flip flops for extended timer/event counter
Merge pull request #44 from ramiropolla/steppers

steppers: add absolute position
Taito device tilemap assert fixes, and clean up of obsolete stuff (nw)