[tex-hyphen] String preparation

[Élie Roux]

> maybe 32 can be used for that

Looks good!

> (btw, i assume that you realize that such features are rather
> specific and special purpose and are not that likely to be supported
> identical across macro packages i.e. should be used very carefully in
> patterns that are shared)

Sure! I don't think these will be supported by polyglossia or babel
natively, they'll certainly be used only by hand for
"micro-hyphenation". I'll advertise that for Latin though, providing a
snippet. (most people using liturgical Latin use LuaLaTeX because
Gregorio is built on top of it)

This solution solves many very difficult use cases so thanks a lot!

Thank you,
-- 
Elie