typespeed v0.6.0

- A new mechanism for game rules has been integrated. With these
  game rules, you can change the way typespeed works.
- The high score file format has yet changed again: this time a
  csv format is in use. Also there is only one huge file that contains
  all game results (not just top 10). Especially usefull if you want
  to create statistics about your improvements. :)
- The binary is setgid games now, but drops privileges as soon as
  high score file is opened. With this step, there is no need any longer
  to create world writeable high score files.

