distributed installations, where the immediate installation location
is different from the final installation location, but in the case
where it is not desirable to put the entire install hierarchy as a
subdirectory of DESTDIR.
the python preprocessor version, the techfiles and .magicrc file
will get the correct arguments, without affecting the use of CPP
in the configure script.
python3 preprocessor is captured in the variable MCPP, not CPP,
since CPP is meaningful to the make process. Also, the
MAGICDIR variable in the name needed to be escaped so that the
variable is not evaluated within the configure script.
Tim Edwards