sample: Implement custom move semantics for event_queue

The default move constructor and assignment operator do not invalidate
the rhs object and destroy the currently hold wl_event_queue.
Fix a typo in the usage help
Add an option to ignore events

This option is useful when generating a wrapper for wl_display, because
Wayland sets its own listener and handles the events internally. There
is no need to expose handlers for these events to clients.