Operation: Join
Issue #56
Removed unused test function
Merge upstream/master into OperationJoin2

Conflicts:
	rxjava-core/src/main/java/rx/Observable.java
Merge upstream/master into OperationJoin2

Conflicts:
	rxjava-core/src/main/java/rx/Observable.java
Merge pull request #514 from akarnokd/OperationJoin2

Operation Join again