e.g. <opencv2/core/core.hpp> become <opencv2/core.hpp>

Also renamed <opencv2/core/opengl_interop.hpp> to <opencv2/core/opengl.hpp>

Made all STL usages explicit to be able automatically find all usages of
particular class or function.

fixed possibly inccorrect interval measurements in flann's timer (bug #1165). Note: this may break binary compatibility, but since the class is not wrapped in Java and not exposed in Windows API, for example (it's considered internal-use class for flann), the effect should be minimal

this fixes 64-bit MSVC warning

This reverts commit 54d68da8.

fix gcc C++11 bug mentioned in http://answers.opencv.org/question/283 . Bug also fixed in FLANN upstream

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