added cv::sqrt to T-API (using built-in sqrt OpenCL function)
fixed UMat sync problems
Merge pull request #1983 from ilya-lavrenov:tapi_umat
Merge pull request #1981 from ilya-lavrenov:tapi_sqrt
added cv::equalizeHist to T-API
Merge pull request #1974 from ilya-lavrenov:tapi_equalizehist