zlib library interface

[Tiago Dionizio <tngd@...>]

Hi again,

at this point i did some work on a zlib interface for lua, enabling one to
use the compression features of zlib directly from lua.

interested parties can access it at http://mega.ist.utl.pt/~tngd/lua

-Tiago