change the code.
No long use smaller window to the last sweep.
Fix a bug when doing the refinement: make sure to call computeCUDAConfig(_depthMap->getWidth(), _depthMap->getHeight(), N, 1); before using depthRefinement. This bug still exists in the previous version. It is not big deal, but only h*h of the subimage applies the depthmap refinement.

Signed-off-by: Enliang <ezheng@cs.unc.edu>