Interface and demo for disparity filtering, basic WLS implementation

Bugfix Normalization / Enhance "float/double" mode queries for DAISY.

Bug fix for feature extraction

BugFix & Enhance DAISY.

According to CartToPolar() function documentation, result angles could be in range (0..360). To prevent index overflow this check is important.

fixed several warnings in opencv_contrib (text, xfeatures2d)

fixed several warnings in opencv_contrib (text, xfeatures2d); added tesseract installation mini-guide in text/readme.md

Add rotation invariance option for BRIEF descriptor.

Added basic interface and demo for disparity filtering, added unoptimized fast weighted least
squares filter implementation. Current demo tests domain transform, guided and
weighted least squares filters on a dataset, measures speed and quality.

bugfix4269 included remarks in http://answers.opencv.org/question/59293/...

Added python support, updated Retina class documentation

Add DAISY descriptor for wide-baseline / keypoints.

Code to grab the red lined polygon from Google Maps

Adding the LATCH descriptor

Features2d fixes

wrapping remaining xfeature2d classes to scripting