yeah, so I added some sharing buttons... so?
fixed StringMatchSequence.getIterator

now it's consistent with the synchronous iterator (and String.match)
Sequence constructor does not need an argument
added async test for async match

also refactored into createAsyncTest helper
added FilteringIterator to make async filtering efficient
made heading bigger on homepage
optimized asynchronous iteration per suggestion (see #6)
updated aliases
factored out this.indexed checks

...moved logic directly into IndexedSequence.prototype
unimportant