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

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

change the download channels to oclchannles()
fix bugs of arithm functions
perf fix of bilateral
bug fix of split test case
add build_warps functions

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

Signed-off-by: yao <bitwangyaoyao@gmail.com>