make the inclusion of NHUUID support the default in hints files

On macOS, the required underlying pieces are in there.

On Linux, we try to test for the presence of libuuid and
the uuid.h header files. If the tests are both successful,
we proceed to include NHUUID support.

On either macOS or Linux, NO_NHUUID=1 on the Make command
line will forcibly prevent the inclusion of the support for NHUUID.

sys/unix/hints/include/multiw-2.370

@@ -168,10 +168,6 @@ CPLUSPLUS_NEED_DEPSUPPRESS = 1
 endif   # WANT_WIN_QT6
 endif   # WANT_WIN_QT
 
-ifdef WANT_NHUUID
-USE_UUIDLIB=1
-endif
-
 ifeq "$(GIT)" "1"
 ifndef GITSUBMODULES
 GITSUBMODULES=1

sys/unix/hints/linux.370

@@ -227,11 +227,46 @@ ifdef MAKEFILE_SRC
 ifdef CURSESLIB
 WINLIB += $(CURSESLIB)
 endif   #CURSESLIB
-ifdef WANT_NHUUID
+
+ifneq "$(NO_NHUUID)" "1"
+UUID_LIB_CHECK := $(shell echo `/sbin/ldconfig -p | grep libuuid`)
+#$(info UUID_LIB_CHECK=$(UUID_LIB_CHECK))
+ifneq "$(UUID_LIB_CHECK)" ""
+UUID_LIB=1
+else
+UUID_LIB=0
+endif
+#$(info UUID_LIB=$(UUID_LIB))
+#
+# check for uuid development headers
+UUID_HEADERS_CHECK := $(wildcard /usr/include/uuid/uuid.h)
+#$(info UUID_HEADERS_CHECK=$(UUID_HEADERS_CHECK))
+ifneq "$(UUID_HEADERS_CHECK)" ""
+UUID_HEADERS = 1
+else
+UUID_HEADERS = 0
+endif
+#$(info UUID_HEADERS=$(UUID_HEADERS))
+
+ifeq "$(UUID_LIB)" "1"
+ifeq "$(UUID_HEADERS)" "1"
+ifndef WANT_NHUUID
+WANT_NHUUID=1
+endif
+endif
+endif
+else    # NO_NHUUID
+WANT_NHUUID=0
+endif   # NO_NHUUID
+
+ifeq "$(WANT_NHUUID)" "1"
+#$(info NHUUID support will be included)
 CFLAGS+= -DNHUUID
 LIBS+=-luuid
-endif   #NHUUID
-endif   #MAKEFILE_SRC
+else    # WANT_NHUUID
+$(info Attention - No NHUUID support will be included)
+endif   # WANT_NHUUID
+endif   # MAKEFILE_SRC
 
 ifdef WANT_WIN_X11
 USE_XPM=1

sys/unix/hints/macOS.370

@@ -216,11 +216,18 @@ LFLAGS += -framework AVFoundation
 endif
 
 ifdef MAKEFILE_SRC
+ifndef NO_NHUUID
+# macOS doesn't need any extra prerequisite libraries
+# so do this unconditionally, unless NO_NHUUID=1 is
+# passed on the Make command line.
+WANT_NHUUID=1
+endif  #NO_NHUUID
+
 ifdef WANT_NHUUID
 CFLAGS += -DNHUUID
 UUIDOBJ = macuuid.o
 endif
-endif
+endif  #MAKEFILE_SRC
 
 #
 #-INCLUDE multisnd1-pre.370