Log Message:
Update to 0.4.2:
* 0.4.2 (20-04-2004)
  - actually applied the map switching fixes (doh!)
  - fixed compilation for Mandrake 9.1 and Slackware 9.1
  - revamped campaign system
  - added support for difficulty levels (handicaps)
  - added player selection when playing against the computer
  - added default mission soundtrack
  - 'createunit' events now work with arbitrary locations
  - added support for changing squad size and initial xp for units
  - added 'handicap' trigger
  - lots of minor fixes and featurelets