Propagated inputs

[Andreas Enge <andreas@enge.fr>]

Hello,

polkit builds two libraries, polkit-agent and polkit-gobject. According to
pkg-config, the second one
   Requires: gio-2.0 >= 2.18 glib-2.0 >= 2.18,
while the first one requires nothing.

So I decided to not propagate the glib input (which also contains gio), as
potentially one could use the first library without glib. Or is it our
policy to propagate inputs as soon as any of the built libraries requires
them?

Andreas