glib-networking module

[Dan Winship <danw gnome org>]

As part of the proxy support for GSocket that recently landed in glib,
we had to put part of the code into a separate git module to avoid
circular dependencies (because that code depends on libproxy, but
libproxy depends on glib). So there is now an additional module
(glib-networking) that is required in order to get full functionality
from glib 2.26. (If you install glib 2.26 without glib-networking then
it effectively just disables automatic proxy detection, which means that
the networking code works exactly the same as it did in 2.24.)

I am not sure what needs to be done about this, release-wise. Eg, there
are various module lists it needs to be added to, I guess? (Notably
jhbuild's.) I don't want a separate bugzilla product for it (there's
already a "networking" component under the "glib" product), but it will
probably get its own ftp.gnome.org directory, since there doesn't seem
to be any way to make "install-module" install it into glib's directory.

-- Dan