[12] Review request: 8209040: Change JavaFX release version to 12

[Kevin Rushforth]

Please review the following to bump the feature version (aka major 
version) of openjfx to 12:

https://bugs.openjdk.java.net/browse/JDK-8209040
http://cr.openjdk.java.net/~kcr/8209040/webrev/
As a note, I will wait to push this until the repo is tagged with 11+22 
(the RDP2 build). I will then add a 12+0 tag, following by the changeset 
for this fix to bump the version to 12.

-- Kevin