- enforced fx application thread - added a headful test `TestThreadingRestrictions`
## Note to the Reviewers To avoid merge conflicts, the preferred order of integrations: #1697 #1713 #1717 ------------- Commit messages: - fixed node init test - all tests - initial test Changes: https://git.openjdk.org/jfx/pull/1717/files Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=1717&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8350048 Stats: 472 lines in 11 files changed: 429 ins; 14 del; 29 mod Patch: https://git.openjdk.org/jfx/pull/1717.diff Fetch: git fetch https://git.openjdk.org/jfx.git pull/1717/head:pull/1717 PR: https://git.openjdk.org/jfx/pull/1717
