fix macOS use of -dead_strip_dylibs, install major version lib symlinks.

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

While calc on macOS will execute if linker used with "-dead_strip_dylibs"
and CUSTOM is defined, other applications that use libcalc but not
libcustcalc (such as sample_many and sample_rand) will fail to execute
due to missile symbols.  Therefore "-dead_strip_dylibs" is not used
by default when ALLOW_CUSTOM is "-DCUSTOM" under macOS.
Thanks to GitHub user @TurtleWilly for bringing to our attention,
problems related to use of  "-dead_strip_dylibs".

When installing shared libraries, libcalc.x.y.z will be a link
to the libcalc shared library and libcustcalc.x.y.z will be a link
to the libcustcal shared library.

CHANGES

@@ -87,18 +87,24 @@ The following are the changes from calc version 2.14.3.1 to date:
     Added Makefile variable ${VER} to hold the calc major release version.
     The calc major release version is a 3 level version (x.y.z).
 
-    Under macOS, the current version of both libcalc and
+    Under macOS, the current version of both libcalc and libcustcalc
-    libcustcalc are set to the current calc major release version.
+    shared libraries are set to the current calc major 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 macOS linker is used with "-dead_strip".
+    In particular, the macOS linker is used with "-dead_strip" by default.
 
     While calc on macOS will execute if linker used with "-dead_strip_dylibs"
     and CUSTOM is defined, other applications that use libcalc but not
     libcustcalc (such as sample_many and sample_rand) will fail to execute
     due to missile symbols.  Therefore "-dead_strip_dylibs" is not used
     by default when ALLOW_CUSTOM is "-DCUSTOM" under macOS.
+    Thanks to GitHub user @TurtleWilly for bringing to our attention,
+    problems related to use of  "-dead_strip_dylibs".
+
+    When installing shared libraries, libcalc.x.y.z will be a link
+    to the libcalc shared library and libcustcalc.x.y.z will be a link
+    to the libcustcal shared library.
 
 
 The following are the changes from calc version 2.14.2.1 to 2.14.3.0:

Makefile

@@ -290,8 +290,8 @@ OBJS= ${LIBOBJS} ${CALCOBJS} ${UTIL_OBJS} ${SAMPLE_OBJ}
 #
 CALC_STATIC_LIBS= libcalc.a libcustcalc.a
 CALC_DYNAMIC_LIBS= libcalc${LIB_EXT_VERSION} libcustcalc${LIB_EXT_VERSION}
-SYM_DYNAMIC_LIBS= libcalc${LIB_EXT} \
+SYM_DYNAMIC_LIBS= libcalc${LIB_EXT} libcustcalc${LIB_EXT} \
-	libcustcalc${LIB_EXT_VERSION} libcustcalc${LIB_EXT}
+	libcalc${LIB_EXT_VER} libcustcalc${LIB_EXT_VER}
 EARLY_TARGETS= hsrc .hsrc custom/.all custom/Makefile
 
 # list of sample programs that need to be built to satisfy sample rule
@@ -483,6 +483,10 @@ libcalc${LIB_EXT}: libcalc${LIB_EXT_VERSION}
 	${Q} ${RM} -f $@
 	${LN} -s $? $@
 
+libcalc${LIB_EXT_VER}: libcalc${LIB_EXT_VERSION}
+	${Q} ${RM} -f $@
+	${LN} -s $? $@
+
 ###
 #
 # calc documentation
@@ -2370,6 +2374,10 @@ libcustcalc${LIB_EXT}: libcustcalc${LIB_EXT_VERSION}
 	${Q} ${RM} -f $@
 	${LN} -s $? $@
 
+libcustcalc${LIB_EXT_VER}: libcustcalc${LIB_EXT_VERSION}
+	${Q} ${RM} -f $@
+	${LN} -s $? $@
+
 ###
 #
 # building calc-static and static lib*.a libraries
@@ -3392,9 +3400,6 @@ install: ${LIB_H_SRC} ${BUILD_H_SRC} calc.1 all custom/Makefile
 		echo "installed ${T}${LIBDIR}/libcalc.a"; \
 	   fi; \
 	fi
-	${Q}# NOTE: The this makefile installs libcustcalc${LIB_EXT_VERSION}
-	${Q}#       because we only want to perform one ${LDCONFIG} for both
-	${Q}#       libcalc${LIB_EXT_VERSION} and libcustcalc${LIB_EXT_VERSION}.
 	-${Q} if [ -f libcalc${LIB_EXT_VERSION} ]; then \
 	    if ${CMP} -s libcalc${LIB_EXT_VERSION} \
 			 ${T}${LIBDIR}/libcalc${LIB_EXT_VERSION}; then \
@@ -3418,6 +3423,11 @@ install: ${LIB_H_SRC} ${BUILD_H_SRC} calc.1 all custom/Makefile
 		${LN} -f -s libcalc${LIB_EXT_VERSION} \
 			    ${T}${LIBDIR}/libcalc${LIB_EXT}; \
 		echo "installed ${T}${LIBDIR}/libcalc${LIB_EXT}"; \
+		echo ${LN} -f -s libcalc${LIB_EXT_VERSION} \
+			    ${T}${LIBDIR}/libcalc${LIB_EXT_VER}; \
+		${LN} -f -s libcalc${LIB_EXT_VERSION} \
+			    ${T}${LIBDIR}/libcalc${LIB_EXT_VER}; \
+		echo "installed ${T}${LIBDIR}/libcalc${LIB_EXT_VER}"; \
 	    fi; \
 	fi
 	-${Q} if [ -f custom/libcustcalc${LIB_EXT_VERSION} ]; then \
@@ -3443,6 +3453,11 @@ install: ${LIB_H_SRC} ${BUILD_H_SRC} calc.1 all custom/Makefile
 		${LN} -f -s libcustcalc${LIB_EXT_VERSION} \
 			    ${T}${LIBDIR}/libcustcalc${LIB_EXT}; \
 		echo "installed ${T}${LIBDIR}/libcalc${LIB_EXT}"; \
+		echo ${LN} -f -s libcustcalc${LIB_EXT_VERSION} \
+			    ${T}${LIBDIR}/libcustcalc${LIB_EXT_VER}; \
+		${LN} -f -s libcustcalc${LIB_EXT_VERSION} \
+			    ${T}${LIBDIR}/libcustcalc${LIB_EXT_VER}; \
+		echo "installed ${T}${LIBDIR}/libcalc${LIB_EXT_VER}"; \
 		if [ -z "${T}" -o "/" = "${T}" ]; then \
 		    if [ ! -z "${LDCONFIG}" ]; then \
 			echo "running ${LDCONFIG}"; \

Makefile.config

@@ -1313,6 +1313,7 @@ VER= 2.14.3
 #
 LIB_EXT= .so
 LIB_EXT_VERSION= ${LIB_EXT}.${VERSION}
+LIB_EXT_VER= ${LIB_EXT}.${VER}
 
 # standard utilities used during make
 #