Log Message:
Update xmess to 0.85.

Changes since 0.84.1nb1:
- Everything from MAME 0.85 (http://x.mame.net/changes-mame.html) and
  MESS 0.85 (http://x.mame.net/changes-mess.html).
- Added a 2x sinc-based 6-tap filter effect with scanlines, enabled
  via "-effect 8" or "-ef 8".  (Richard Goedeken)
- Reworked the input code so that it more closely resembles its Windows
  counterpart.  This adds support for "-steadykey", \ 
"-a2d_deadzone" and
  "-digital".
- Increased the maximum number of joysticks from 6 to 8 and the maximum
  number of buttons per joystick from 16 to 32.
- Mouse buttons may not have been working in recent releases for games
  such as Missile Command; they should work now.
- Network support is broken for the time being because of the core
  input changes, so please disable XMAME_NET in your makefile.  If
  you're interested in fixing this, have a look at src/unix/network.c
  and the XMAME_NET sections of an older src/inptport.c.