Fixed introlab#197 (handling zed pose confidence == -1)

Fixed inf loop when all signatures are loaded in WM and if a signatur…

…e has a -1 word

Fixed a bug where camera facing polygons were not textured

Loop closure view: Added legend "gray" color for features not quantiz…

…ed in vocabulary (-1)

fixed texture not exported with single image scan

Memory: ignore reextract features when registration is not visual

UCv2Qt: fixed min/max of depth to grayscale conversion for CV_32FC1 type

Backward compatibility (DBViewer, DBReader) with old database format …

…not saving CameraModel's image size, cx and cy

Fixed introlab#137

RTABMapConfig.cmake: added find VTK if vtkGUISupportQt target is requ…

…ired