urlchange usage patterns

1

Currently only single key change is supported ?key=only

I'd like to capture events for when multiple keys have changed

#?key-one&key-two  -- AND
#?key-one|key-two  -- OR can be handled with chained .on().on()

2

When key is removed hash or entirely removed to #?, event is not trigger. This would help to detect reset mode.

3

Document how to reset url state to home hash.