refactored generalized hough (both CPU and GPU):

removed set/get methods from Algorithm (implement owns)
removed GHT_* enumeration
gabor filter docs Bug#1894
ref in inpainting docs
pydocs for cv2.findTransformECC
added gridTransform/gridCopy overloads for GlobPtrSz
added globPtr for GpuMat
added cudev::GpuMat_<T> support to Input/Output arrays
rewrote matrix operations with cudev module
Removed CV_EXPORTS from all template classes (that I could find).

It doesn't make sense to export template classes, since there's no way
the user can learn that it can import them. In fact, it is somewhat
deleterious, because every module will export every instantiation
that it uses, but doesn't inline.
epilines pydocs
morphologyex docs bug#2169
imshow docs improvement bug#2490
docs changes
docs changes
Merge pull request #1162 from jet47:cudev-integration
Merge pull request #1149 from jet47:generalized-hough-refactoring
Merge pull request #1186 from SpecLad:dont-export-templates
Merge pull request #1265 from abidrahmank:misc_docs2