RFC: Adding zlib dependency to libgio

[Alexander Larsson <alexl redhat com>]

I've been working on some API for gio (more details later) that involves
having an API for (de)compression. Having this as a public API makes
zlib a mandatory dependency for libgio (and thus the glib tarball).

We already have a dependency on zlib from gdk-pixbuf, so all Gtk+ apps
already pull this in, however there could be non-gtk+ using glib apps
that now get an additional dependency. Its a very small (74K .so) and
very widely availible/used library though, so I don't think this is a
huge deal.

Anyone who thinks this is a bad idea?