The current code relies on the assumption that the first invocation will never specify no_throttle=True.
However that puts us in a pickle when writing unit tests: if we had a fictitious:
def setup_platform():
update()
@Throttle(MIN_TIME_BETWEEN_SCANS)
def update():
pass
Then given multiple tests, the second and some of subsequent tests would be throttled (depending on timing).
But we also can't change that code to call `update(no_throttle=True)' because that's not currently accepted.
This diff shouldn't change the visibile behavior of any component, but allows this extra flexibility.