Basic doxygen documentation support

- updated existing Doxyfile.in
- added corresponding cmake instructions
- added some specific files (layout, icon)
- clean existing doxygen warnings

Conflicts:
	CMakeLists.txt
	doc/CMakeLists.txt
	modules/core/include/opencv2/core.hpp
	modules/core/include/opencv2/core/base.hpp
	modules/core/include/opencv2/core/cuda.inl.hpp
	modules/core/include/opencv2/core/mat.hpp
	modules/core/include/opencv2/core/matx.hpp
	modules/core/include/opencv2/core/types.hpp
	modules/flann/include/opencv2/flann/lsh_table.h
	modules/imgproc/include/opencv2/imgproc.hpp
iOS framework build script changes

- buildbot process support (break build in case of errors)
- disabled some warnings in cmake script
Fixed iOS framework compilation warnings
iOS framework build script changes from master branch
superres: Fix return value VideoFrameSource_GPU

superres module fails to compile with the following error messages:

[100%] Building CXX object modules/superres/CMakeFiles/opencv_superres.dir/src/super_resolution.cpp.o
/opencv-2.4.10/modules/superres/src/frame_source.cpp: In function 'cv::Ptr<cv::superres::FrameSource> cv::superres::createFrameSource_Video_GPU(const string&)':
/opencv-2.4.10/modules/superres/src/frame_source.cpp:263:16: error: expected type-specifier before 'VideoFrameSource'
/opencv-2.4.10/modules/superres/src/frame_source.cpp:263:16: error: could not convert '(int*)operator new(4ul)' from 'int*' to 'cv::Ptr<cv::superres::FrameSource>'
/opencv-2.4.10/modules/superres/src/frame_source.cpp:263:16: error: expected ';' before 'VideoFrameSource'
/opencv-2.4.10/modules/superres/src/frame_source.cpp:263:41: error: 'VideoFrameSource' was not declared in this scope
/opencv-2.4.10/modules/superres/src/frame_source.cpp:264:1: error: control reaches end of non-void function [-Werror=return-type]
cc1plus: some warnings being treated as errors
make[3]: *** [modules/superres/CMakeFiles/opencv_superres.dir/src/frame_source.cpp.o] Error 1
make[3]: *** Waiting for unfinished jobs....

This is caused because the return value of the createFrameSource_Video_GPU function should be a VideoFrameSource_GPU object.
fixing SVM negative value rounding
Merge pull request #3364 from mshabunin:doxygen-docs-24
Merge pull request #3382 from StevenPuttemans:fix_3982
Merge pull request #3376 from vriera:2.4
Merge pull request #3294 from mshabunin:fix-ios-warnings-24