Common fixes:
- print function
- int / float division
- map, zip iterators in py3 but lists in py2

Known bugs with opencv 3.0.0
- digits.py, called via digits_video.py: https://github.com/Itseez/opencv/issues/4969
- gaussian_mix.py: https://github.com/Itseez/opencv/pull/4232
- video_v4l2.py: https://github.com/Itseez/opencv/pull/5474

Not working:
- letter_recog.py due to changed ml_StatModel.train() signature

fixes for latest changes in opencv3.0 api

waitKey() normalization

fixed mser bindings

Also, removed the one from modules/python/src2/cv.py and cleared its
executable bit, since it's not a script.

all video processing samples use camera as default source (and fallback to synth in case of capture error)

fixed "import cv" in the new python samples. corrected Python bindings to match the documentation and vice versa (NOTE: in cv2.stereoCalibrate the parameter ordering has been changed)

added color_histogram.py sample
work on VideoSynth (chessboard)

simple video capture and synth framework stub
edge detection sample