FFmpeg now requires that frames allocated with avcodec_alloc_frame are
freed with avcodec_free_frame.

(cherry picked from commit 77578d41)

Conflicts:
	modules/highgui/src/cap_ffmpeg_impl.hpp

The HAVE_DOC_GENERATOR variable was always true.

(cherry picked from commit 3d46c1f9)

Conflicts:
	doc/CMakeLists.txt

... before any exceptions occur.

(cherry picked from commit 08da247a)

(cherry picked from commit 16ce114e)

    modules/videoio/src/cap_gstreamer.cpp:577:31: error: invalid suffix on literal; C++11 requires a space between literal and identifier [-Wreserved-user-defined-literal]
            filename = "v4lsrc ! "COLOR_ELEM" ! appsink";
                              ^
    modules/videoio/src/cap_gstreamer.cpp:585:32: error: invalid suffix on literal; C++11 requires a space between literal and identifier [-Wreserved-user-defined-literal]
            filename = "v4l2src ! "COLOR_ELEM" ! appsink";

looks like Maksim was right; the new fix does not do the second attempt to detect python libs, it finds it correctly with the first attempt

- note: uses VFPv3 instructions
- also added overloaded cvRound variants with float and int parameters
- thanks to Marina Kolpakova from Itseez for idea
- thanks to developers from #llvm IRC channel for help with inline asm

explained reason why IPP is disabled on 32-bit Linux. disable IPP's minMaxLoc_32f on 32-bit OSes only

2) disable IPP on 32-bit Linux when OpenCV is built as shared libs. Otherwise we get linker errors
3) disable IPP's minMaxIdx 32-bit floating-point flavor in a hope that it fixes some test failures