This is the final version of the 4.x series and a patch version bump.
There is a 5.x series, but this likely needs to be moved to a jna4 port
and the dependencies updated before doing so.  I've done some light
testing of elasticsearch6 with this without seeing any problems.

This does not compile with Java 11.  I haven't tried 6, 7, 9 or 10, but
all of those are potentially going away soon, so it is kind of pointless
to do so.