- added webp (lossy and lossless without alpha channel)
- added tests

Evangelidis, G.D. and Psarakis E.Z. "Parametric Image Alignment using Enhanced
Correlation Coefficient Maximization", IEEE Transactions on PAMI, vol. 32, no.
10, 2008

find_package(OpenCV) should not include_directories by default, that is not standard afaik. Plus that creates problems when creating the ROS package :)

adjust matchTemplate in performance sample, as current version is too slow when template size isn't small

some improvements of existing sse3 optimization of bilateral filter in case of 8uc3. Now perf tests take 6120ms instead of previous 7250ms (1.18x speed-up)