gdbm binding updated

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

I've updated my Lua binding for gdbm. It's cleaner now.
I've also added a sample implementation of a repository of precompiled chunks
using gdbm.

The code is available at ftp://ftp.tecgraf.puc-rio.br/pub/lhf/gdbm.tar.gz .
(When lua-users.org adds a code repository, I'll move it there...)

Please send me your suggestions and comments.
Thanks.
--lhf