+ Added these mandatory files.
  * doc/:
    + Wrote a Doxygen configuration file.
    + Added a manpage for caca-config(1), borrowed from sdl-config.
  * configure.ac:
    + Use new style AC_INIT.
    + Error out if no library was found.
    + Added *djgpp* to the list of non-PIC platforms.
    + Added checks for doxygen and latex.