TIFF build was fixed;
Direct Show back-end was enabled;
More accurate guards implemented.

GPU module turned off;
TIFF support turned off;
Windows Managment and Video IO (VFW) turned off.

* removed OpenGLFuncTab, now extensions are loaded internally
* added support of GlBuffer and GlTexture2D to InputArray/OutputArray
* added ELEMENT_ARRAY_BUFFER and PIXEL_PACK_BUFFER targets
* added copyFrom/copyTo method for GlBuffer and GlTexture2D
* removed GlFont
* removed pointCloudShow
* removed OpenGLCleanCallback
* added Access parameter to GlBuffer::mapHost
* added autoRelease parameter to all create methods

These codes should be included into regular builds.

removed void integral(const GpuMat& src, GpuMat& sum, GpuMat& sqsum, Stream& stream) - it fails with NPP_NOT_IMPLEMENTED error
updated docs, accuracy and performance tests

minor build system changes (now cuda code in opencv_core is compiled using CUDA_ARCH* cmake variables)

added GlBuffer, GlTexture and GpuMat support to InputArray
replaced addTextOpenGl function by render + GlFont

replaced "const InputArray&" => "InputArray"; made InputArray and OutputArray references. added "None()" constant (no array()).

a big patch; use special proxy types (Input/OutputArray, Input/OutputArrayOfArrays) for passing in vectors, matrices etc.

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 - cvAddButton changed to match requirement
 - CV_GUI_NORMAL and CV_GUI_EXPANDED done
 - context menu with right click

 - cvAddButton done
 - All the "actions" of the toolbar are working
 - Window properties done

- 3 new points mostly done:
      - OpenGL support enabled (windows are rendered using GPU)
      - Save current screen (with overlay and so on...) with shortcut CTRL+S
      - Text rendering (with any system font, and possibility to set the style - normal, italic,... - the weight - normal, bold, ... - the color, the spacing between letters, and so on...)