Camera support progress

[fernando_c_m]

pinhole:3927): GLib-GObject-WARNING **: 08:22:41.659: specified class size for type 'CameraWindow' is smaller than the parent type's 'HdyApplicationWindow' class size

(pinhole:3927): GLib-GObject-WARNING **: 08:22:41.659: cannot add private field to invalid (non-instantiatable) type '<invalid>'

(pinhole:3927): GLib-CRITICAL **: 08:22:41.660: g_once_init_leave: assertion 'result != 0' failed

(pinhole:3927): GLib-GObject-CRITICAL **: 08:22:41.660: g_object_new_valist: assertion 'G_TYPE_IS_OBJECT (object_type)' failed

(pinhole:3927): GLib-GObject-CRITICAL **: 08:22:41.660: g_object_ref_sink: assertion 'G_IS_OBJECT (object)' failed

(pinhole:3927): Gtk-CRITICAL **: 08:22:41.660: gtk_window_present_with_time: assertion 'GTK_IS_WINDOW (window)' failed

This is the console output of pinhole at the moment