call closedir() at end of iteration in file.readdir()
make error message more likely to be correct
add message for case when event is not an array of two elements
add SIG* constants to signal
some extra parser test cases
aesthetic adjustments
new methods for List and OrderedList: clear(), iterkeys(), itervalues(), iteritems()
consistently use evtype and evdata for the two event parameters
don't check return value of signal.kill()
add sys.exit()
test time.sleep() in both sync and async context
trying to define precise scheduler semantics with tests