v0.5.0

• core
  • add TermCriteria for iterative algorithms
• imgproc
  • add CornerSubPix() and GoodFeaturesToTrack() for corner detection
• objdetect
  • add DetectMultiScaleWithParams() for HOGDescriptor
  • add DetectMultiScaleWithParams() to allow override of defaults for CascadeClassifier
• video
  • add CalcOpticalFlowFarneback() for Farneback optical flow calculations
  • add CalcOpticalFlowPyrLK() for Lucas-Kanade optical flow calculations
• videoio
  • use temp directory for Windows test compat.
• build
  • enable Appveyor build w/cache
• osx
  • update env path to always match installed OpenCV from Homebrew