Allow to take screen screenshots

[AlexanderZobkov]

To understand why particular test cases failed, sometimes, it's not enough to have an error message returned by Junit or/and log files. Especially when tests are run in CI environment.
To simplify troubleshooting of failed tests, screenshots (of the entire screen and/or a particular window only) can be taken during execution of unit tests.

[mikeliucc]

Any updates on this?

[renatoathaydes]

This is a very good issue to be solved by a new contributor, given that both Swing and JavaFX make it pretty easy to do so.

I have been working on many other projects, so if this is left up to me, I am sorry but it will take a few months for me to get around to doing it.