msg: introduce message versioning

msg/versioned/ConfigOverrides.msg

@@ -0,0 +1,21 @@
+# Configurable overrides by (external) modes or mode executors
+
+uint32 MESSAGE_VERSION = 0
+
+uint64 timestamp		# time since system start (microseconds)
+
+bool disable_auto_disarm         # Prevent the drone from automatically disarming after landing (if configured)
+
+bool defer_failsafes             # Defer all failsafes that can be deferred (until the flag is cleared)
+int16 defer_failsafes_timeout_s  # Maximum time a failsafe can be deferred. 0 = system default, -1 = no timeout
+
+
+int8 SOURCE_TYPE_MODE = 0
+int8 SOURCE_TYPE_MODE_EXECUTOR = 1
+int8 source_type
+
+uint8 source_id                  # ID depending on source_type
+
+uint8 ORB_QUEUE_LENGTH = 4
+
+# TOPICS config_overrides config_overrides_request