We should be able to have tests that run in a complete JavaFX system with Glass, Prism and Quantum but share an Application instance so that we don't have to start a new VM for each test file.

We can have these tests use the Monocle headless implementation of Glass and the Prism SW pipeline by default, since these exist on all platforms and can be run as part of the automated build. However these tests should be able to run using any JavaFX configuration.