build: simple top level makefile

this is to make it easier to integrate with static analysis tools

Makefile

@@ -0,0 +1,27 @@
+# top level makefile to build SITL for primary vehicle targets. 
+# Useful for static analysis tools
+
+all: sitl
+
+sitl: TARGET=sitl
+sitl: plane copter rover antennatracker
+
+linux: TARGET=linux
+linux: plane copter rover antennatracker
+
+clean: TARGET=clean
+clean: plane copter rover antennatracker
+
+.PHONY: plane copter rover antennatracker
+
+plane:
+	make -C ArduPlane $(TARGET)
+
+copter:
+	make -C ArduCopter $(TARGET)
+
+rover:
+	make -C APMrover2 $(TARGET)
+
+antennatracker:
+	make -C AntennaTracker $(TARGET)