Merge pull request #1128 from PX4/uavcan

Basic UAVCAN support

Tools/check_submodules.sh

@@ -53,4 +53,28 @@ else
 	git submodule update;
 fi
 
+
+if [ -d uavcan ]
+then
+	STATUSRETVAL=$(git submodule summary | grep -A20 -i uavcan | grep "<")
+	if [ -z "$STATUSRETVAL" ]
+	then
+		echo "Checked uavcan submodule, correct version found"
+	else
+		echo ""
+		echo ""
+		echo "uavcan sub repo not at correct version. Try 'git submodule update'"
+		echo "or follow instructions on http://pixhawk.org/dev/git/submodules"
+		echo ""
+		echo ""
+		echo "New commits required:"
+		echo "$(git submodule summary)"
+		echo ""
+		exit 1
+	fi
+else
+	git submodule init
+	git submodule update
+fi
+
 exit 0