RFR: 8284956: Potential leak awtImageData/color_data when initializes X11GraphicsEnvironment

[Zhengyu Gu]

During initializing native data of `X11GraphicsEnvironment`, a single `AwtGraphicsConfigData` is used/reused, not only failed cases, but also succeeded cases. So `AwtGraphicsConfigData` internal states need to be cleanup properly to avoid memory leaks.

Test:
- [x] jdk_awt

-------------

Commit messages:
 - Merge branch 'master' into JDK-8284956-memleak_awtImageData_awt_allocate_colors
 - cleanup
 - v1
 - v0

Changes: https://git.openjdk.java.net/jdk/pull/8317/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=8317&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8284956
  Stats: 36 lines in 1 file changed: 25 ins; 4 del; 7 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8317.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8317/head:pull/8317

PR: https://git.openjdk.java.net/jdk/pull/8317