[luatex] BOM

[Javier Bezos]

> to be determined by the format, but catching it is not easy
> and very likely a callback will be necessary to read the
> string of bytes at the beginning of the file (I presume it's
> possible).

:-/. Well, I'm not sure, because luatex by default requires valid 
utf8 byte sequences, and most of the arrays of bytes are not
(remember we are still at the very beginning of the file).

Javier