Basic takeUntil implementation
Tests for TakeUntil
Merge branch 'master' into TakeUntiFunctional

Conflicts:
	rxjava-core/src/main/java/rx/Observable.java
Refactored TakeUntil operator
Basic MostRecent implementation
Unit tests for MostRecent Operator
Updated Observable API
Implemented GetIterator operation
Implemented Defer Operation
implemented OperationDematerialize
added dematerialize api to observable
unit test for OperationDematerialize
updated dematerialize unit tests to use mockit
optimize imports
Updated logic to match Rx.NET
Refactored TakeUntil to use TakeWhile.
Cleaned up comment
Merge pull request #151 from mairbek/TakeUntiFunctional

Implemented TakeUntil operation
Merge branch 'dematerialize' of git://github.com/prabirshrestha/RxJava into dematerialize-merge

- added Javadoc for @throws Exception
- suppressed unchecked warnings

Conflicts:
	rxjava-core/src/main/java/rx/Observable.java
Merge pull request #177 from benjchristensen/dematerialize-merge

Operator: Dematerialize - review and manual merge