Added unistd header so it compiles on iOS
Additional amends so it compiles on iOS
Merge branch 'master' of https://github.com/Itseez/opencv

# By Ilya Lavrenov (11) and others
# Via OpenCV Buildbot (33) and others
* 'master' of https://github.com/Itseez/opencv: (43 commits)
  ocl morphology fix
  eliminated restriction delta == 0 from cv::sepFilter2D
  case-insensitivity
  added 3-channels support to cv::Canny
  doc fix
  Added guard to prevent from gpu module redefinition in OpenCV.mk
  changing default perf strategy from BASIC (old) to SIMPLE (new, faster)
  Implicit linkage with CUDA runtime reverted.
  Multiple fixes in camera.
  added gpu type selection in OPENCV_OPENCL_DEVICE parser
  added 3-channels support to optimized version
  adding missing include (fixing 'no ocl implementation' error)
  Native camera fix for some deivices with Qualcomm SoC like Samsung Galaxy S4.
  Libraries filter update after abs path cut.
  Workaround for Intel platform: replace min() with ternary operator
  switching to CV_HAAR_SCALE_IMAGE mode, enabling test
  enabling OCL LBP branch for all devices
  changed epsilon for test pass on Win32
  enabled 3-channels support for cv::createSuperResolution_BTVL1
  Fixed incorrect thread synchronizations
  ...