Updating STAR detector and FREAK descriptor to work with large and/or 16-bit images
Don't automatically convert to grayscale (keep previous behavior.)
Merge branch 'master' of https://github.com/Itseez/opencv

Conflicts:
	modules/imgproc/src/sumpixels.cpp
Merge branch 'master' of https://github.com/Itseez/opencv

Conflicts:
	modules/features2d/include/opencv2/features2d.hpp
	modules/features2d/src/freak.cpp
	modules/features2d/src/stardetector.cpp
Merge pull request #1932 from seth-planet:master