Forgot to update so code after previous fix

added comments in gpu.hpp

This was crashing my code:
    for( size_t i = 1; i < imagePoints.size(); i++ )
        objectPoints.push_back(objectPoints[0]);

Changed by:
objectPoints.resize(imagePoints.size(),objectPoints[0]);

Plus clean up on Qt code

--no commit message

avoid extra gpu memory allocation in BP and CSBP