Update comments in Makefile to support Developer Studio

Makefile

 export MANGOH_ROOT = $(shell pwd)
 
-MKSYS_ARGS_COMMON = -s ${MANGOH_ROOT}/apps/GpioExpander/gpioExpanderService
+MKSYS_ARGS_COMMON = -s $(MANGOH_ROOT)/apps/GpioExpander/gpioExpanderService
 MKSYS_ARGS_GREEN =
-MKSYS_ARGS_RED = -s ${MANGOH_ROOT}/apps/RedSensorToCloud
+MKSYS_ARGS_RED = -s $(MANGOH_ROOT)/apps/RedSensorToCloud
 
+# The comments below are for Developer Studio integration. Do not remove them.
+# DS_CLONE_ROOT(MANGOH_ROOT)
+# DS_CUSTOM_OPTIONS(MKSYS_ARGS_COMMON)
+# DS_CUSTOM_OPTIONS(MKSYS_ARGS_GREEN)
+# DS_CUSTOM_OPTIONS(MKSYS_ARGS_RED)
 
 .PHONY: all
 all: green_wp85 green_wp750x red_wp85 red_wp750x
 
 .PHONY: green_wp85
 green_wp85:
-	mksys -t wp85 ${MKSYS_ARGS_COMMON} ${MKSYS_ARGS_GREEN} mangOH_Green.sdef
+	mksys -t wp85 $(MKSYS_ARGS_COMMON) $(MKSYS_ARGS_GREEN) mangOH_Green.sdef
 
 .PHONY: green_wp750x
 green_wp750x:
-	mksys -t wp750x ${MKSYS_ARGS_COMMON} ${MKSYS_ARGS_GREEN} mangOH_Green.sdef
+	mksys -t wp750x $(MKSYS_ARGS_COMMON) $(MKSYS_ARGS_GREEN) mangOH_Green.sdef
 
 .PHONY: red_wp85
 red_wp85:
-	mksys -t wp85 ${MKSYS_ARGS_COMMON} ${MKSYS_ARGS_RED} mangOH_Red.sdef
+	mksys -t wp85 $(MKSYS_ARGS_COMMON) $(MKSYS_ARGS_RED) mangOH_Red.sdef
 
 .PHONY: red_wp750x
 red_wp750x:
-	mksys -t wp750x ${MKSYS_ARGS_COMMON} ${MKSYS_ARGS_RED} mangOH_Red.sdef
+	mksys -t wp750x $(MKSYS_ARGS_COMMON) $(MKSYS_ARGS_RED) mangOH_Red.sdef
 
 .PHONY: clean
 clean: