STYLE: remove unused private fields (foamyMesh)

- simplify handling of warnings for surfaceBooleanFeatures

applications/utilities/surface/surfaceBooleanFeatures/Make/options

@@ -1,20 +1,22 @@
 EXE_NDEBUG = -DNDEBUG
 /* EXE_NDEBUG = -g -O0 -DFULLDEBUG */
 
-c++CGALWARN = -Wno-old-style-cast
 
 /*-- Define NO_CGAL in COMP_FLAGS to avoid using CGAL altogether */
 /*-- Define CGAL_INEXACT to use inexact CGAL constructions */
 
-ifeq (,$(findstring NO_CGAL,$(COMP_FLAGS)))
-include $(GENERAL_RULES)/cgal
+ifneq (,$(findstring NO_CGAL,$(COMP_FLAGS)))
+  include $(GENERAL_RULES)/no-cgal
+  c++LESSWARN :=
+else
+  include $(GENERAL_RULES)/cgal
 endif
 
 EXE_INC = \
     ${ROUNDING_MATH} \
     ${EXE_NDEBUG} \
     ${CGAL_INC} \
-    ${c++CGALWARN} \
+    ${c++LESSWARN} \
     $(COMP_FLAGS) \
     -I$(LIB_SRC)/fileFormats/lnInclude \
     -I$(LIB_SRC)/surfMesh/lnInclude \