mocha: set slow threshold to 500ms, use spec output for now
when a waiter throws: dont pre-empt other waiters, dont consider promise really finished until waiters succeed
Promise.wrap renamed to Promise.call;

also trying out the try/finally form for fun in a few places
add a sanity check to $.type.register
cleanup some test (proper names, etc)
rebuild
dont touch Promise.call (its abuiltin name)
rebuild