initial version of msg to uorb script

Standard and embedded types work, may need small refinements for some
types

msg/std_msgs/Header.msg

@@ -0,0 +1,15 @@
+# Standard metadata for higher-level stamped data types.
+# This is generally used to communicate timestamped data 
+# in a particular coordinate frame.
+# 
+# sequence ID: consecutively increasing ID 
+uint32 seq
+#Two-integer timestamp that is expressed as:
+# * stamp.sec: seconds (stamp_secs) since epoch (in Python the variable is called 'secs')
+# * stamp.nsec: nanoseconds since stamp_secs (in Python the variable is called 'nsecs')
+# time-handling sugar is provided by the client library
+time stamp
+#Frame this data is associated with
+# 0: no frame
+# 1: global frame
+string frame_id