Support newer versions of OpenCV built from source

[psyhtest]

The versions of OpenCV we currently support are quite old:

$ ck search package --tags=lib,opencv,channel-stable
ck-math:package:lib-opencv-3.4.5
ck-math:package:lib-opencv-3.3.0
ck-math:package:lib-opencv-2.4.13.2
ck-math:package:lib-opencv-3.4.3
ck-math:package:lib-opencv-3.2.0

The latest releases are 3.4.10 and 4.3.0. (Intel used 4.1.2 in the MLPerf Inference v0.5 submission.)

Adding support for 3.4.10 should be quite easy:

0. Test you can build OpenCV 3.4.3 on your system:

$ ck install package --tags=lib,opencv,v3.4.3

1. Fork repo:ck-math to your GitHub account e.g. i_want_to_help.

2. Switch your local repo:ck-math to your new remote fork and create a branch there: e.g.

$ cd `ck find repo:ck-math`
$ git remote set-url origin git@github.com:i_want_to_help/ck-math
$ git checkout -b opencv-3.4.10

3. Create a copy of the OpenCV 3.4.3 package:

$ ck cp ck-math:package:lib-opencv-3.4.3 ck-math:package:lib-opencv-3.4.10

4. Modify the copy to replace "3.4.3" with "3.4.10" everywhere in meta.json.

5. Test you can build the new package:

$ ck install package --tags=lib,opencv,v3.4.10

6. Commit the change and push your branch to your remote.

7. Issue a Pull Request from your remote to https://github.com/ctuning/ck-math.

8. Repeat on another system (Windows, MacOS?)

9. Try the same with the latest OpenCV 4.x version.

[psyhtest]

A much better approach to copying would be to create a new ck-math:package:lib-opencv with variations for different versions and options. For example:

• package:lib-openvino
• package:lib-armnn