Change events to have an array of "void *" references, and give the

Change events to have an array of "void *" references, and give the
event posting functions varargs to fill these.

Attribute g_call_me() to appropriate g_geom's where necessary.

Add a flag argument to g_call_me() methods which will be used to signal
cancellation of events in the future.

This commit should be a no-op.