Removed the ${CAL_PASSDOWN}, ${HELP_PASSDOWN}, ${HELP_PASSDOWN},
${CSCRIPT_PASSDOWN} Makefile variables as the new Makefile
include files keep Makefile variables in sync.
Fixed the ability of calc to compile when CUSTOM is undefined
(i.e., -UCUSTOM). The libcustcalc is always built, regardless
of the $(ALLOW_CUSTOM} Makefile variable. However when CUSTOM
is undefined, the bulk of custom functions are not defined.
6ee34e709d