improve macOS shared library building and use by calc

Dropped the use of Makefile variable ${SET_INSTALL_NAME}.
Under macOS it was always needed, elsewhere it was not.

Under macOS, the current version of both libcalc and
libcustcalc are set to the current calc release version.

Under macOS, to reduce dependency chains, we remove functions and
data that are unreachable by the entry point or exported symbols.
In particular, the linker is run with "-dead_strip".

CHANGES

@@ -35,6 +35,8 @@ The following are the changes from calc version 2.14.3.1 to date:
     The calc version 2.14.3.0 is the last release that supported
     the Makefile.simple and custom/Makefile.simple files.
     Now, a make that supports makefile conditional syntax is required.
+    The simple target, a target that only was used for Makefile.simple
+    was removed.
 
     Moved makefile variables that configure calc and configure how to
     compile calc from Makefile into a new Makefile.config file.
@@ -47,10 +49,11 @@ The following are the changes from calc version 2.14.3.1 to date:
 
     Now, the Makefile.config file will consistently configure
     calc and how calc is compiled and built by all calc Makefiles.
+    The custom/Makefile no longer includes Makefile.
 
-    The platform target section from the old Makefile has been moved to
-    a new file, Makefile.target.  The custom/Makefile no longer includes
-    Makefile.
+    The platform target section from the old Makefile has been moved
+    to a new file, Makefile.target.  Improved the format and comments
+    in target information.
 
     The Makeifle includes the Makefile.target file.
     The cal/Makeifle includes the Makefile.target file.
@@ -78,8 +81,15 @@ The following are the changes from calc version 2.14.3.1 to date:
     of the $(ALLOW_CUSTOM} Makefile variable.  However when CUSTOM
     is undefined, the bulk of custom functions are not defined.
 
-    Added comments in Makefile.local for how to reduce dependency chains
-    under macOS.  XXX - this doesn't yet work so don't uncomment - XXX.
+    Dropped the use of Makefile variable ${SET_INSTALL_NAME}.
+    Under macOS it was always needed, elsewhere it was not.
+
+    Under macOS, the current version of both libcalc and
+    libcustcalc are set to the current calc release version.
+
+    Under macOS, to reduce dependency chains, we remove functions and
+    data that are unreachable by the entry point or exported symbols.
+    In particular, the linker is run with "-dead_strip".
 
 
 The following are the changes from calc version 2.14.2.1 to 2.14.3.0:

Makefile.local

@@ -85,13 +85,3 @@
 # LDFLAGS+= -Wno-invalid-command-line-argument ${FSANITIZE} -fno-omit-frame-pointer
 # CALC_ENV+= ASAN_OPTIONS=detect_stack_use_after_return=1
 ####
-
-####
-# To reduce dependency chains under macOS:
-#
-# This comment block was tested under:
-#
-#	macOS 13.5 with clang version 14.0.3 (clang-1403.0.22.14.1)
-#
-# LDFLAGS+= -Wl,-dead_strip_dylibs -Wl,-dead_strip
-####