* Fixes issue 16777.

* core: update Concurrency getNumThreads()

Intelligent scissors

* Start

* Remove whitespace

* Re onMouse

* replased double to float

* Draw contours

* CV_FILLED -> FILLED

* Remove line 210

* Change 'about'

* Remove M_PI

* Remove warning

* CP_PI

* double to float

* CV_PI to Float

* Add struct for data

* line 172, 191 whitespace

* Change name

* Fix Warnings

* Set const

* line 180

* rewrite keys

* &img = param->img

  There's no need to use `vec_perm()` instead of `vec_splat()`,
  since instruction `vperm` is quite heavy compared to `vsplt[b,h,w]`.

* Supported Flatten for constant nodes

* Added default axis

* Refactoring

* Refactoring

* Added cast layer

* Fix comments

* Add Cast for layers

- HETERO plugin doesn't switch well between devices

 - avoid overflow in own::Mat::total() and according tests, part 2

- avoid overflow in own::Mat::total() and according tests

Problem is that iter1 += tcols, iter2 += tcols are called without check.
row < trows - 1 check is processed after increment in "for" statements.

- replaced bitwise &= on bools, with explicit && to make KW happy