Call EVBC::onBegin from your OnBegin
callout. If -restart is on, a new instance of the event
builder will be started (and the old one killed off). If the Event
builder is being started, if you have defined a proc or command named
startEVBSources that will be invoked
after the event builder pipeline has been started.
If the event builder pipeline is not restarted, this command will also call EVBC::reset preparing the event builder for the potential that the timestamps in the data acquisition hosts have been reset.