Changed getting of heading. For path heading now return NaN if vehicle
at layover. This is useful since when deadheading the vehicle is likely
not to be traveling in direction of path! And for heading changed so
that if path heading not valid then looks in AVL history for last valid
heading instead of just at the last AVL report.
Moved isLayover and nextStopId from IpcExtVehicle to IpcVehicle so that
it is available to the XML/JSON API. This is nice for determining if
vehicle is wrongly matching ahead to layover.
Merge branch 'master' of ssh://git@github.com/Transitime/core.git