RFR: 8217472: Add attenuation for PointLight [v15]

[Nir Lisker]

> CSR: https://bugs.openjdk.java.net/browse/JDK-8218264

Nir Lisker has updated the pull request incrementally with one additional commit since the last revision:

  Addressed review comments

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

Changes:
  - all: https://git.openjdk.java.net/jfx/pull/43/files
  - new: https://git.openjdk.java.net/jfx/pull/43/files/21f91dd7..e1fdf8e2

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jfx&pr=43&range=14
 - incr: https://webrevs.openjdk.java.net/?repo=jfx&pr=43&range=13-14

  Stats: 36 lines in 3 files changed: 25 ins; 4 del; 7 mod
  Patch: https://git.openjdk.java.net/jfx/pull/43.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/43/head:pull/43

PR: https://git.openjdk.java.net/jfx/pull/43