Fix FD event constant usage, and implement FD remove event
Fix FD event constant usage, and implement FD remove event

JGulic/libvirt-glib,JGulic/libvirt-glib,JGulic/libvirt-glib,libvirt/libvirt-glib,JGulic/libvirt-glib,libvirt/libvirt-glib,JGulic/libvirt-glib,libvirt/libvirt-glib