new contact address

[Luiz Henrique de Figueiredo <lhf@...>]

Due to excessive spam, lua@tecgraf.puc-rio.br no longer works.

The new address is at
	http://www.lua.org/authors.html

There are also new addresses for sending uses forms and surveys.
Sorry about that.
--lhf