[luatex] Fribidi for LuaTeX

[Taco Hoekwater]

Hi,

Now that the Unicode BiDi algorithm implementation discussion
seems to restart, it is a good time to ask the people involved
to solve the non-trivial problem of adjusting the algorithm
to cater for the inclusion of

* out-of-line node objects (\setbox, \box, \copy),
* out-of-line tokens (like alignment templates and macro expansions),
* vertical typesetting,
* TeX grouping levels,
* Interfering nodes (math, \special, \rule etc)

Thanks in advance,

Taco