flattenScan's function argument shouldn't be named
Add concat
Add zipWith
Fix Observable.single definition
Add Stream.error constructor
Add Stream.materialize
Implement global dematerialize
Added Stream.fromSequence and takeLast
Add takeUntil
Add Stream.catch
Allow CompositeDisposable to be inited with a list
Add Observable.sample
Merge pull request #7 from jspahrsummers/concat-and-zip

Add a bunch of additional stream operators