Don't feed mkdependC -D__GNUC__ + fix-fix to mkdependC

Delete temp files when through with it

fix SCRIPT_SUBST_VARS.

Use $(CPP), not $(RAWCPP).  This involves saving the cpp output to a
temporary file.  This change should fix 'make depend' on RedHat 5.

When needed , define __linux__ to silence cpp warnings

cygwin32 hacks

Use eval exec .. trick rather than #!

Catch (another) gcc include file site

Major update to more-or-less 2.02

New Build System!