Implement Observable.takeUntil()
Fix test case for Observable.buffer(timestamp)

As of now it just replicates the behaviour of the test case for
Observable.buffer(count).
Implement Observable.bufferWithTimeout()
Shorten onComplete() in Observable.buffer()
Fix Observable.takeUntil()
Fix Observable.bufferWithTimeout()
Fix test case for takeUntil()
Fix typos
Remove Observable.bufferWithTimeout()
Add myself to the list of authors
Merge pull request #8 from tindzk/master

Implement Observable.takeUntil()