We want to use the vfunc of the class to implement devices coming from a
Qemu object on D-Bus, but we don't want to expose that in public API.
Instead, we can keep the object instance and class internal but still
expose the subclasses as public API. We have to do old-style class
definitions to do that, but worth the ability to keep public API limited
so that we can make changes later.
This library doesn't do much yet. It contains the scaffolding and the
rough shape of what I think the API should be in mks-types.h. Some of the
types have some skeleton implementation as well to hid the D-Bus API
behind those types.
The next steps are to fill out the other wrapper objects and see what
properties we should expose from the underlying D-Bus proxies.
Along with that, will be a GtkWidget which can have a number of properties
set on it to specify the MksScreen, MksKeyboard, and MksMouse devices. It
may make sense to attach the session + screen to the widget, so that it can
adapt to keyboard and mouse changes though.
