[luatex] new commands in luatex 1.08/9

[David Carlisle]

While checking the latex interfaces for the luatex update, the
following primitives which don't seem to be in the manual came up


    + compoundhyphenmode
    + endlocalcontrol
    + fixupboxesmode
    + gtoksapp
    + gtokspre
    + mathflattenmode
    + mathrulethicknessmode
    + xtoksapp
    + xtokspre

from the names and a quick look at the sources, we can see what some
of them do, but are these experimental additions that may go, or are
they new primitives that just missed the manual in the current
revision.  Either way some hints of what they do would be useful,
thanks:-)

David