Saclib 2.2 & higher system dependent files & configuration

0) System-dependent configuration is done by calling
   $saclib/bin/sconf, which in turn calls 
   $saclib/bin/mksysdep.pl, which tries to diagnose the 
   processor type and OS type and call the "install" script 
   from the appropriate (we hope!) subdirectory of
   $saclib/sysdep.

2) To add a port, you need a subdirectory for the target
   system in $saclib/sysdep, and you need to modify
   $saclib/bin/sconf to recognize your target system
   and call the appropriate install.

NOTE: The macosX86 port is for Mac OS X on x86 in 32-bit
      mode.  Presumably, the port to 64-bit Mac OS X wouldn't
      be too hard given the 64-bit Linux on x86 port. 
