evalDetection Normalization

First pass at issue #202 Finds height/width ratio of associated ground truth and increases predicted bb height by this ratio.  
Yes I tested a few values ranging from 0.1 to 0.5 (the value for a true positive) and 0.3 seemed to produce the best average overlap.  This was done on only VJ so I'll do the same for a couple of the other detectors to verify this.