[Rev 02] RFR: 8238080: FXMLLoader: if script engines implement javax.script.Compilable compile scripts

[Rony G.Flatscher]

> This PR adds a "compile" process instruction to FXML files with the optional PI data "true" (default) and "false". The
> PI data is turned into a boolean value using "Boolean.parseBoolean(String)".
> This makes it possible to inject the compile PI everywhere in a FXML file and turn on and off compilation of scripts if
> the scripting engine implements the javax.script.Compilable interface. The PR adds the ability for a fallback in case
> compilation of scripts fails, in which case a warning gets issued about this fact and evaluation of the script will be
> done without compilation. Because of the fallback scripts get compiled with this version by default.
> ---------
> ### Progress
> - [x] Change must not contain extraneous whitespace
> - [x] Commit message must refer to an issue
> - [ ] Change must be properly reviewed
> 
> ### Issue
>  * [JDK-8238080](https://bugs.openjdk.java.net/browse/JDK-8238080): FXMLLoader: if script engines implement
>    javax.script.Compilable compile scripts
> 
> 
> ### Download
> `$ git fetch https://git.openjdk.java.net/jfx pull/192/head:pull/192`
> `$ git checkout pull/192`

Rony G. Flatscher has updated the pull request with a new target base due to a merge or a rebase. The pull request now
contains 27 commits:

 - Updates to meet Kevin's comment in PR 192 as of May 27th.
 - Merge remote-tracking branch 'upstream/master' into scriptCompilablePIcompileFallback
 - Reword the compile processing instructions (replace 'Hint' with 'Note:', adjust text to context), remove spurious empty
   line in script example code.
 - Document the compile processing instruction for scripts.
 - Add missing language processing instruction.
 - Correct typo, replace tabs, remove trailing blanks.
 - Make sure we test the default behaviour to compile script by leaving out the compile PI.
 - Revert temporary rename of test method.
 - Correct ModuleLauncherTest (remove non-existing test), correct formatting.
 - Always supply the script's filename in the error message first to further ease spotting the location of script
   exceptions.
 - ... and 17 more: https://git.openjdk.java.net/jfx/compare/6bd0e22d...7ef1bd68

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

Changes: https://git.openjdk.java.net/jfx/pull/192/files
 Webrev: https://webrevs.openjdk.java.net/jfx/192/webrev.02
  Stats: 2545 lines in 29 files changed: 2516 ins; 2 del; 27 mod
  Patch: https://git.openjdk.java.net/jfx/pull/192.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/192/head:pull/192

PR: https://git.openjdk.java.net/jfx/pull/192