If this seems too wordy, take into account a new user who tries to find out extent of FP16 support in OpenCV.

* add universal intrinsics for HSV2RGB_b

* rewritten HSV2RGB_b without using extra universal intrinsics

* removed unused variable

* undo changes in v_load_deinterleave

fixes handling of empty matrices in some functions (#11634)

* a part of PR #11416 by Yuki Takehara

* moved the empty mat check in Mat::copyTo()

* fixed some test failures

* Update Intel's Inference Engine deep learning backend

* Remove cpu_extension dependency

* Update Darknet accuracy tests

Typo fixes (#11631)