Add HoughTransform examples python2

houghlines.py for HoughLinesP() and HoughLines()
houghcircles.py for HoughCircles()
Merge pull request #779 from sivapvarma:master
fixed compilation with CUDA
fix build without gpu module with cuda
Merge pull request #784 from jet47:fix-gpu-build
Merge pull request #786 from cuda-geek:fix-build-gpu-off-cuda-on
Make imgproc.hpp independent from C API
Make highgui.hpp independent from C API
Make photo.hpp independent from C API
Make flann headers independent from OpenCV C API
Update documentation
Fix build errors