Log Message:
Update to 021212.

The data file needed for sound is installed into ${PREFIX}/share/xrick/data.zip.
Either copy it to your current dir, or start xrick with
	xrick -data ${PREFIX}/share/xrick/data.zip

Changes:
* Reworked the build system so xrick can easily be built on Unix boxes as
  well as on non-Unix boxes (do not rely on symbolic links, etc.).
* Use function keys instead of numeric keys for various game controls, as some
  non-US keyboard require that SHIFT is pressed for numbers (A. Majorel).
* Fixed a potential buffer overflow in command-line parameters handling
  (A. Majorel).
* Joystick is (hopefully) OK now (S. Chauveau).
* Implemented all sounds: music, effects, etc.
* The sound was horrible on Windows due to a poorly dimensionned sound
  buffer. Fixed.
* Re-ripped all sounds. This time I used STeem with debugger to save each
  sound as a WAV file, then Audacity to filter an annoying static noise
  produced by STeem, then SOX to re-sample.