[jfx15] RFR: 8246343: Fix mistakes in FX API docs [v2]

[Nir Lisker]

> Fixes https://bugs.openjdk.java.net/browse/JDK-8246343 and some additional fixes in the vicinity.

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/274/files
  - new: https://git.openjdk.java.net/jfx/pull/274/files/29271615..5c7d74ef

Webrevs:
 - full: https://webrevs.openjdk.java.net/jfx/274/webrev.01
 - incr: https://webrevs.openjdk.java.net/jfx/274/webrev.00-01

  Stats: 2 lines in 2 files changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jfx/pull/274.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/274/head:pull/274

PR: https://git.openjdk.java.net/jfx/pull/274