Pull requests:
#943 from jet47:cuda-5.5-support
#944 from jet47:cmake-2.8.11-cuda-fix
#912 from SpecLad:contributing
#934 from SpecLad:parallel-for
#931 from jet47:gpu-test-fixes
#932 from bitwangyaoyao:2.4_fixBFM
#918 from bitwangyaoyao:2.4_samples
#924 from pengx17:2.4_arithm_fix
#925 from pengx17:2.4_canny_tmp_fix
#927 from bitwangyaoyao:2.4_perf
#930 from pengx17:2.4_haar_ext
#928 from apavlenko:bugfix_3027
#920 from asmorkalov:android_move
#910 from pengx17:2.4_oclgfft
#913 from janm399:2.4
#916 from bitwangyaoyao:2.4_fixPyrLK
#919 from abidrahmank:2.4
#923 from pengx17:2.4_macfix
Conflicts:
modules/calib3d/src/stereobm.cpp
modules/features2d/src/detectors.cpp
modules/gpu/src/error.cpp
modules/gpu/src/precomp.hpp
modules/imgproc/src/distransform.cpp
modules/imgproc/src/morph.cpp
modules/ocl/include/opencv2/ocl/ocl.hpp
modules/ocl/perf/perf_color.cpp
modules/ocl/perf/perf_imgproc.cpp
modules/ocl/perf/perf_match_template.cpp
modules/ocl/perf/precomp.cpp
modules/ocl/perf/precomp.hpp
modules/ocl/src/arithm.cpp
modules/ocl/src/canny.cpp
modules/ocl/src/filtering.cpp
modules/ocl/src/haar.cpp
modules/ocl/src/hog.cpp
modules/ocl/src/imgproc.cpp
modules/ocl/src/opencl/haarobjectdetect.cl
modules/ocl/src/pyrlk.cpp
modules/video/src/bgfg_gaussmix2.cpp
modules/video/src/lkpyramid.cpp
platforms/linux/scripts/cmake_arm_gnueabi_hardfp.sh
platforms/linux/scripts/cmake_arm_gnueabi_softfp.sh
platforms/scripts/ABI_compat_generator.py
samples/ocl/facedetect.cpp
remove as much warnings as possible
use enum instead of MACRO for ocl.hpp
add command line parser in accuracy test and perf test
some bug fix for arthim functions
add getoclcontext and getoclcommandqueue so that other opencl program can interactive with opencv ocl module
correct haar test cases
add face detection sample
add OCL 1.2 feature for setTo
bug fix of integral
replace the error code -217 with suitable MACRO
simplify tests, no need apply a new context for each test case
add more control for tests in utility.hpp
