improve the cal/regress.cal regress test suite structure

Improve comments about use of the ${CALC_ENV} Makefile variable.
Noted in Makefile.cal where and how the ${CALC_ENV} is used.
Use ${CALC_ENV} Makefile variable were needed.

Modified regression test cal/regress.cal: in some cases test numbers
were adjusted.  Add comments indicate which test numbers apply to
which code.  Indicated where there is room for new tests.
Expanded the end of test numbers from 9999 to  99999.

Makefile.config

@@ -1225,20 +1225,24 @@ PURIFY=
 #LD_DEBUG= -lmalloc_cv
 LD_DEBUG=
 
-# When doing a:
+# Environment variables for local directory calc execution and local directory calc testing
+#
+# These environment variables are used in the following rules:
 #
 #	make check
 #	make chk
 #	make debug
+#	make testfuncsort
+#	make prep
+#	make run
 #
-# the ${CALC_ENV} is used to supply the proper environment variables
-# to calc.  Most people will simply need 'CALCPATH=./cal' to ensure
-# that these debug rules will only use calc resource files under the
-# local source directory.
+# NOTE: An equivalent environment variable setting is found in .lldbinit for lldb use.
 #
-# If in doubt, use:
-#
-#	CALC_ENV= CALCPATH=./cal LD_LIBRARY_PATH=.:./custom DYLD_LIBRARY_PATH=.
+# When calc is installed on the local system, it is assumed that variables such as
+# ${LIBDIR} will be set to the default LD_LIBRARY_PATH for the system.  Thus for
+# normal execution outside of the special rules mentioned in this comment block,
+# the system wide defaults for shared libraries will be used AND that one does NOT
+# need to use set these environment variables for normal calc use.
 #
 ifeq ($(ALLOW_CUSTOM),-DCUSTOM)
 CALC_ENV= CALCPATH=./cal LD_LIBRARY_PATH=. DYLD_LIBRARY_PATH=. CALCHELP=./help \