700 marker tracking

[saniokazzz]

Trying to use the library with larger number of markers(currently have 700) the target is lower performance tablets, but it runs quite bad even on normal PC. targetLost event is emitting only after 20-30 seconds after actual marker was lost. Tried to work-around it with manual objects hiding from scene some milliseconds after last targetUpdate, however the scan functionality still strung in MindAR internals for another 20-30 prior becoming responsive.