Retargeting JBS bugs to openjfx15

[Kevin Rushforth]

Now that we are in RDP1 for openjfx14, it's time to move all 
enhancements and most P4-P5 bugs (excluding doc and test bugs) to 
openjfx15. I plan to do a bulk move for these bugs shortly. If an 
assignee of a particular P4 bug later wants to propose a PR for the 
jfx14 branch, and if the reviewers agree it is safe enough and worth 
getting in, then the JBS bug can have its fix version updated back to 
openjfx14.

Additionally, many P3 bugs should be moved, but that can be done on a 
case-by-case basis.

-- Kevin