Add several master event handler test stubs.
Cover master onDrain and onEmpty handlers.
Cover master onMessage handler.
Cover master cluster events.
Test names "should" begin consistently.
Rename 'event handler' suite -> 'Handler'.
DRY-up master Method test class instantiation.
Add pending tests for remaining master API methods.
Cover master getNextFile()
Cover master sendWorkers()
Cover master runQueue()
Cover master startQueue()
Cover master buildFile()