LCF for lua formatting

[TamaMcGlinn]

The only lua formatter currently included is specifically for Lua 5.1, which is not the latest version. Lcf works for all lua versions, hence I suggest to add it to vim-codefmt.

[dbarnett]

Heh yeah, to be fair to luaformatterfiveone they never made any pretense of supporting other lua versions, weird as that approach is.

Hopefully LCF would be strictly better (once they get their stdin wrinkles etc sorted out) and the other one could be removed or deemphasized.