Features camera singleton marek

Added camera select window.

Bude treba otestovat funkcionalitu. Usage:
Ziskanie kamery:
CapVideo mCapVideo = OpenCV::CamSelectCore::getInstance()->selectCamera();
Kontrola na NULL ci kameru vratilo:
if (mCapVideo==NULL) error
Ziskanie matice:
Mat mat = mCapVideo->queryFrame();
Release kamery: (ak nie je NULL)
mCapVideo->release();