Plugins
Plugins are C/C++ shared libraries loaded by the binding to execute some
simple routine. Routine could be on reception of a new signal or at sources
initialization time or signal subscription with the respective JSON field
onReceived init and getSignals
A default plugin (builtin) is provided with 2 functions:
- defaultOnReceived: set and record a new signal value and its timestamp
 in the signal composer service. It simply tooks the incoming event JSON object
 and search for key valueandtimestampthen call functionsetSignalValue.
- setSignalValueWrap: a lua2cfunction the could be called from any LUA script to record a new signal value.
CAUTION:
timestampvalue has to be typed as uint64_t with a nanosecond precision using a realtime clock. To correctly store it in a JSON-C object use the int64 type with the according fonctions: json_object_new_int64() json_object_get_int64() json_object_set_int64() ...