marker_infoTWO not allocated using Tracker

[Netich]

I use Tracker.h in my application, not TrackingSingleMarker. In 2.2, marker_infoTWO was allocated both in Tracker constructor, and TrackingSingleMarker::init.

In 2.3 you deleted the allocation in Tracker.cpp, so it crashes. Since it is allocated only if it is not NULL, i cant see the reason not to keep both, so Tracker can be used too.

Thanks