Original pull requests:
#996 from jet47:gpu-nvcuvid-libraries
#995 from jet47:fix-bug-2985
#999 from snosov1:unreliable-results-fix
#1005 from alekcac:doc_fix
#1004 from jet47:fix-bug-3068
#987 from jet47:bug-3085-fix
#969 from pengx17:2.4_binary_cache
#929 from dominikrose:mingw-libdc1394-2-windows
#1000 from ivan-korolev:fix_sift_bug_2892
#1001 from ivan-korolev:fix_stitching_bug_2405
#998 from asmorkalov:android_cmake_mips_fix
#993 from ivan-korolev:fix_videostab_bug_3023
#988 from snosov1:3071-fix
#986 from pengx17:2.4_initiated_context
#982 from pengx17:2.4_fix_two_bugs
#981 from SeninAndrew:ximea_camera_support_fix
#991 from asmorkalov:android_javadoc_fix
#972 from jet47:mog2-params-bug-2168
#980 from SpecLad:include-config
#973 from pengx17:2.4_oclclahe
#903 from aks2:2.4
#968 from asmorkalov:android_na_cproj_fix
#971 from SpecLad:matchers-ctor
#970 from asmorkalov:dshow_valid_check_fix
#965 from apavlenko:fix_java_empty_mats
Conflicts:
cmake/OpenCVModule.cmake
modules/core/src/matmul.cpp
modules/gpu/CMakeLists.txt
modules/ocl/include/opencv2/ocl/ocl.hpp
modules/ocl/perf/perf_imgproc.cpp
modules/ocl/src/imgproc.cpp
modules/ocl/src/initialization.cpp
modules/stitching/src/matchers.cpp
modules/video/src/video_init.cpp
modules/videostab/src/global_motion.cpp
The video(4) driver provides a Video4Linux2 compatible API for
various video peripherals. This patch propagates HAVE_VIDEOIO if
the sys/videoio.h include file is found, which is the signature of
video(4).
