Log Message:
Update to 0.5:

Changes between 0.4 and 0.5:
  * palette optimisation for the S-Lang driver to work around the colour pair
    shortage bug
  * minor compilation fix

Changes between 0.3 and 0.4:
  * preliminary X11 graphics driver
  * support for simultaneously compiled-in drivers
  * honour the CACA_DRIVER, CACA_GEOMETRY and CACA_FONT environment variables
  * more documentation