RFR: 8313556: Create implementation of NSAccessibilitySlider protocol [v5]

[Alexander Zuev]

> Create implementation for Slider and Stepper accessibility protocols.
> Fix mapping.
> Fix performAction parameter type in declaration.

Alexander Zuev has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains seven additional commits since the last revision:

 - Merge remote-tracking branch 'origin/master' into JDK-8313556
 - Merge pull request #7 from openjdk/master
   
   Merge
 - - Added accessibilityTitle method
   - Removed some debug output generation
 - Merge remote-tracking branch 'origin/master' into JDK-8313556
 - Fixing warnings during build
 - Add commented out debug statements.
 - 8313556:  Create implementation of NSAccessibilitySlider protocol
   
   Create implementation for Slider and Stepper accessibility protocols.
   Fix mapping.
   Fix performAction parameter type in declaration.

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Changes:
  - all: https://git.openjdk.org/jfx/pull/1226/files
  - new: https://git.openjdk.org/jfx/pull/1226/files/d890b2cb..73bf00af

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jfx&pr=1226&range=04
 - incr: https://webrevs.openjdk.org/?repo=jfx&pr=1226&range=03-04

  Stats: 964 lines in 44 files changed: 831 ins; 72 del; 61 mod
  Patch: https://git.openjdk.org/jfx/pull/1226.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1226/head:pull/1226

PR: https://git.openjdk.org/jfx/pull/1226