Makefile - Add SFML as dependency

Makefile

@@ -3,7 +3,7 @@
 include Makeconf
 
 # Auto tracking of headers
-CXX_FLAGS += -MMD
+CXXFLAGS += -MMD
 
 all-modules := $(foreach t,$(TARGETS),$(modules_$(t)))
 
@@ -12,7 +12,7 @@ depfiles := $(patsubst %.o,%.d,$(filter %.o,$(all-modules)))
 -include $(depfiles)
 
 clean-objs := $(TARGETS) $(all-modules) $(depfiles)
-cmd = $(VERBOSE)g++ $(CXX_FLAGS) -o $@ $^
+cmd = $(VERBOSE)g++ $(CXXFLAGS) $(LDFLAGS_$@) -o $@ $^
 msg = $(or $(verb_$@),finalize) $@
 
 ifneq ($V,1)
@@ -34,7 +34,7 @@ test: vgbc.test
 
 %.o: %.cpp
 	@echo " ... build $@"
-	$(VERBOSE)g++ $(CXX_FLAGS) -c -o $@ $<
+	$(VERBOSE)g++ $(CXXFLAGS) -c -o $@ $<
 
 define target_rule
 $(1): $$(modules_$(1))