Vestax VCI-300: Jog control improvements

2013-05-30:
- Ignore jog wheel movements unless the jog wheel surface is touched.
  Exception from this rule: Nudging when playing in scratch mode is
  still possible without touching the sensor plate!
- Different jog sensitivity parameters for cueing and nudging (tempo)
- Increased jog sensitivity for both cueing and nudging

See also:
http://www.mixxx.org/forums/viewtopic.php?f=7&t=4021&start=20#p18581