Avoid certain cases, where the parser created gratuitous event-actions
Remove a redundant test
Remove unused method from EventAction class
Factor out some repeating code into the EventRacerJoinActions class

Additionally, for each event-actions, count the pending joins, which
will help the next timer event compresson changeset.
"Compress" the chain of repeating timer event-actions

This is likely temporary and ad-hoc. The proper way seems to be to
implement some generic graph transformation during the log writeout.
Besides creating a nicer to view graphs, reducing the nmber of states
may speed up the subsequent analysis.