Cleanup of LabeledSkinBase to allow for switching skins - removed null check in listener on graphic's layoutBounds - added removal of listener in dispose
------------- Commit messages: - 8247576: Labeled/SkinBase: misbehavior on switching skin Changes: https://git.openjdk.java.net/jfx/pull/355/files Webrev: https://webrevs.openjdk.java.net/?repo=jfx&pr=355&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8247576 Stats: 147 lines in 2 files changed: 146 ins; 0 del; 1 mod Patch: https://git.openjdk.java.net/jfx/pull/355.diff Fetch: git fetch https://git.openjdk.java.net/jfx pull/355/head:pull/355 PR: https://git.openjdk.java.net/jfx/pull/355
