roiManager: added button copyRoi. Only works when a single Roi is selected. Added additional field in Roi structure: cornersPixelDim
roiManager: added button copyRoi. Only works when a single Roi is selected. Added additional field in Roi structure: cornersPixelDim

.cornersPixelDim contains the pixel values of the polygon defining the
Roi, while .corners takes the scaling into account. When no scaling is
provided, .cornersPixelDim and .corners will contain the same values.

sjunek/matVis