[luatex] combining files with pure LuaTeX

[Arthur Reutenauer]

	Hello Pablo,

  The answer will probably come as a disappointment to you, but this is
not one of the tasks LuaTeX is designed for.  It's not a general
PDF-editing program.  It is of course possible to do what you want using
LuaTeX, but higher-level typesetting systems like LaTeX or ConTeXt are
much better suited for that, and it's not directly related to LuaTeX,
pdfTeX is enough (LaTeX users, for example, are usually advised to use
the pdfpages package, that works well with pdfTeX).

	Arthur