fsm: do not fail completely in ni_fsm_refresh_state
dbus: do not fail on dbus object creation failures
server: do not fail on missed dbus objects

The events may arrive for non-existing devices when they
get deleted [in the kernel] while we're processing them.
nanny: do not fail on events for deleted devices
client: adjusted ifstatus output indenting
netlink: verify if device exists on newlink events