[libvirt] [libvirt-glib 00/20] gconfig: <graphics> configuration work

Hey, This series groups 2 series which were sent previously for review, one from Visarion https://www.redhat.com/archives/libvir-list/2016-August/msg00868.html and one from Fidencio https://www.redhat.com/archives/libvir-list/2016-March/msg00993.html I'm putting them together as they touch the same piece of code and thus conflict with each other. The separation would happen at 11/20 "gconfig: Implement gvir_config_domain_graphics_spice_get_tls_port()" if I were to send these separately. Visarion's changes add support for configuring the <listen> node for the graphics node, and Fidencio's changes add some base classes to make generic configuration of local/remote graphics nodes easier, regardless of their type (VNC/SPICE for example). This incorporate the various changes I suggested during review, in particular it renames _set_listen_nodes() in the original series to just _set_listen(), better naming suggestions welcome. I've also added a few patches of my own which made sense to have for completeness. Christophe