Converting DemoFX to Maven project

[FDelporte]

• Gradle to be removed?
• Unclear what to do with getUsedPipeline and getPrismTryOrder as they use com.sun.prism

Tested on Mac with Java 15

[chriswhocodes]

Thanks Frank!
I think it's OK to remove gradle for now. Can always add it back later if there's a need. I will remove the prism debug, it's not important.

I want to make the video frame grabber work via reflection so it still operates on JFX8 for the part 3 demo :)

[FDelporte]

OK done, Gradle removed

[chriswhocodes]

Hi Frank,
I'm going to do a little work on the pom to make a JDK8 profile (assumes JavaFX still part of JDK) and a JDK11+ profile (uses maven central openjfx) and do reflective version of frame grabbing. Should have an updated patch tomorrow :)

[FDelporte]

+1 👍