the float variant was always shadowed by the int version as
Rect2d is implicitly convertible to Rect.
This swaps things which is fine, as the vector of boxes was always
copied and the computation was done in double.

Update template_matching.markdown

Fixed "template image" should be "source image" in two sentences explaining template matching.

* Support Slice layer with multiple inputs

* Add test

* Supported Resize from PyTorch

* Rewrite test

* Remove Cast layer (supported in #16735)

* Support ConstantOfShape

* Fix tests

* Fix coments

* Remove useless condition

* Fixed failed tests

* 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

- cache value, evaluate once
- better support for MINGW
- anything in 'cv' namespace
- test: dump number of active threads

- FFmpeg 3.4.7

* feature: Add video capture bitrate read-only property for FFMPEG backend

* test: For WIN32 property should be either expected or 0.

Added `IsOneOf` helper function, enabled only for _WIN32.

- Android Manager version is not increased (stuck on 3.49)

dnn(darknet-importer): add grouped convolutions, sigmoid, swish, scale_channels

* update darknet importer to support enetb0-yolo

* remove dropout (pr16438) and fix formatting

* add test for scale_channels

* disable batch testing for scale channels

* do not set LayerParams::name

* merge all activations into setActivation