New operation Finally (issue #43)
Add finally0 to Observable.java .
Missing import
Added nonstatic Observable.finally0
Incoporate review suggestions.

Splits a compound unit test into to parts.
Uses mockito instead of a bespoke test object.
Removes unused import statements.
Changes the order of the Finally action w.r.t. onComplete/onError.
Merge branch 'upstream' into issue43
Incorporate review suggestions.

- Changes finally0 to finallyDo.
- Removes unnecessary subscription-wrapping.
- Handle exceptions in onCompleted/onError
Merge branch 'issue43' of https://github.com/abliss/RxJava into pull-issue-43-merge

Conflicts:
	rxjava-core/src/main/java/rx/Observable.java
Merge pull request #222 from joshgord/pull-issue-43-merge

Pull issue 43 merge