[luatex] convention for lua packages and file names

[Karl Berry]

    maybe prefixing all with simple would do the trick? simplemplib.sty and 
    simplemplib.lua? Or a random two-letter prefix, for example lkmplib, 
    ermplib, ctmplib?

Neither of these seem like a good convention to me, considering we may
have dozens/hundreds of these in the future.

I guess my suggestion remains just "lua" for the prefix for packages
that run with luatex.

luainputenc
luamcallbacks
luamplib
luatextra

Names are hard.