Added tests for position, attitude, system status and status text
Added _stateChanged, _waypointsRetrieved, _waypointsSetSeccessful, _waypointsSetFailed, _waypointTargeted and _waypointAchieved. Removed _rcvdActiveState
Added emit for GPS_RAW_INT, ATTITUDE, SYS_STATUS, STATUS_TEXT. Added methods to support closing the connection. Removed redundant code. Added options to support the new events.
Now uses the state object from common for state management
Initial version, WIP