Move more messages to auto-generation, work on C++ code style

msg/vehicle_global_position.msg

@@ -0,0 +1,20 @@
+# Fused global position in WGS84.
+# This struct contains global position estimation. It is not the raw GPS
+# measurement (@see vehicle_gps_position). This topic is usually published by the position
+# estimator, which will take more sources of information into account than just GPS,
+# e.g. control inputs of the vehicle in a Kalman-filter implementation.
+#
+uint64 timestamp		# Time of this estimate, in microseconds since system start
+uint64 time_utc_usec		# GPS UTC timestamp in microseconds
+float64 lat			# Latitude in degrees
+float64 lon			# Longitude in degrees
+float32 alt			# Altitude AMSL in meters
+float32 vel_n			# Ground north velocity, m/s
+float32 vel_e			# Ground east velocity, m/s
+float32 vel_d			# Ground downside velocity, m/s
+float32 yaw 			# Yaw in radians -PI..+PI.
+float32 eph			# Standard deviation of position estimate horizontally
+float32 epv			# Standard deviation of position vertically
+float32 terrain_alt		# Terrain altitude in m, WGS84
+bool terrain_alt_valid		# Terrain altitude estimate is valid
+bool dead_reckoning		# True if this position is estimated through dead-reckoning