[gpm][PATCH] handle more mice

[Pozsar Balazs]

Hi again!

This patch makes gpm handle up to 8 mice. (arbitrary limit, by a #define).

The opt_double varible is renamed to mice_count to make it consistent with
it's meaning.
I tested it with 4 mice connected, and works great.
Two possible problems:
- in src/gpm.c, around line 988 there's a 'FIXME??', beacuse it wasn't
  clear for me what the original code supposed to do different for
  the first and second mice, and why. But it works :)
- during argument parsing it doesn't check if the MAX_MICE_COUNT is
  reached, so passing to much -M could make it segfault now.


Comments welcome :)

-- 
pozsy