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
Add a new method for initializing KMeans centers that leads to better clusters and thus better retrieval when final centers have to be existing keypoints instead of clusters barycenters.
Do not build apple objective-c codes if using gcc
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
Added  ippiSqrDistanceNorm and ippiCrossCorrNorm to cv::matchTemplate
fixed slow down in getRectSubPix (original patch by Markus JR Mueller); removed some unused variables and functions
disabled some IPP funcs
cv::warpPerspective and cv::warpAffine
cv::transpose
cv::polarToCart
cv::accumulateWeighted
cv::accumulateSquare && cv::acumulateProduct
cv::sqrt
cv::pow
cv::magnitude
cv::medianBlur
cv::boxFilter
cv::flip