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

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

some improvements of existing sse3 optimization of bilateral filter in case of 8uc3. Now perf tests take 6120ms instead of previous 7250ms (1.18x speed-up)

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

Only the code.

Remove unused var "total"
Declare vars as locally as possible

removed rarely used fixed_size parameter from AutoBuffer type, added optional AutoBuffer* but to cvarrToMat in order to speedup CvSeq->Mat conversion; finished conversion of convex hull and related functions to C++

issue #2678

On some platforms sin and cos are calculated in single precision resulting in
diversity of results.