[BEAM-2530] More fixes/upgrades for Java 9 compatibility

[iemejia]

Apart of the fixes it introduces an auto activated profile when using Java 9.

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[iemejia]

Ok, last fixes applied, a really neat progress, notice that almost all Java 9 specific parts are hidden in self-activated profiles, its functionality should be moved into gradle when the time is appropriate. I will soon start to fill specific JIRAs for the pending breaking tests and once that the fix for classloading gets decided and merged (#4497 or #4514).
Other issue for future discussion is if we move from findbugs to spotbugs at some moment because findbugs seems really unmaintained now, so java 9 compatiblity is zero.
PTAL @kennknowles

[kennknowles]

Nice. LGTM.

[kennknowles]

typo

[iemejia]

thx

[kennknowles]

Cool name, but is there a reason for java-next instead of java-9? I actually guess that with the timelines we might be testing with Java 8, 9, 10 at the same time.

[iemejia]

Well the thing I was thinking is that we probably should define our target if we will go for the whole spectrum (9.10,11) or if we asume like the milestone will be the LTS version (11). I will rename it to 9 and we will see how we evolve it depending pn the future releases.

[iemejia]

retest this please