[lltx] upcoming luatexbase update

[Manuel Pégourié-Gonnard]

Hi,

I've got a new release of luatexbase ready, which mainly consists of reading,
polishing and completing user doc for the mcb (multiple callbacks) and modutils
(module identification) subpackages. There are a few incompatible changes,
mainly name changes:

    modutils
        - \luatexUseModule and \luatexRequireModule replaced by
          \RequireLuaModule with a unified syntax.
        - luatexbase.use_module removed (use luatexbase.require_module with
          a single argument instead).
        - luatexbase.module_term removed.
        - removed support for version check using a floating point
    mcb
        - rationalise "list"-type callbacks handling. The new calling

Only the first two points have a real impact in practice. I created an pushed to
github a branch "lltxb", based on current master, of fontspec and luaotfload
with the few adaptations needed.

I also used the occasion to switch them to luatexbase+lualibs instead of
luatextra. There is now a clear separation between the former, which are basic
packages for programmers, and the later, which is a user-level convenience
package. (And you don't want \LuaTeX and {luacode} to be defined as a
side-effect of loading luaotfload or fontspec, I guess.)

Anyway, the point of my message is to suggest coordinating for the next CTAN
upload: to avoid creating a temporary compatibility layer, it would be best if
we could upload the three packages together.

Thanks,
Manuel.