Changes between the old autoconfig and Mubo's revised Version:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- uses autoconf V2.x instead of V1.x
- replaced obsolete macros with newer versions
- replaced 'echo' calls with appropriate message macros
- replaced checks of ${DEFS} (they are no longer supported by autoconf V2.x)
- use result caching
  (will be usefull if packages would be added to the driver distributions
   since they can share the cache file)
- added messages for some checks wich were 'quiet'
- replaced type size check with AC_CHECK_SIZEOF() macro
- added size check for 'short'
- added type check for 'bool' (defines HAVE_BOOL if supported)
- added size check for 'long long' if supported
- added test for ANSI-C compliant compiler (mainly for LDMUD project)
