Merge pull request #1 from smskelley/master

pulling
Hysteresis Thresh. Push
Hyst. Kernel File
Merge pull request #21 from antbanks2014/master

Hysteresis Threshold
Merge pull request #22 from jolson6/master

Added serial versions of the three kernels.
Get serial kernel to compile by using opencv 'at' Mat notation.
Remove unused theta matrix.
Add command line switching ability between opencl and serial versions.
Add overridden parameterless methods and buffer system to support them.
Prevent Hysteresis Thresholding from advancing buffer, since it causes output to be Sobel instead of NMS.
Expand benchmarking to use different ImageProcessors.
Remove wrap-around neighbor inspection, instead ignore edge pixels.
Add OpenCV as an ImageProcessor and add it to the benchmark-suite.
Added changes to serial version of NMS kernel to address Mat objects in using Mat.data[pos] in the hopes that it will increase performance. Also added a fix to the serial Sobel kernel.