Operations toMap (3) and toMultimap (4)
Merge upstream/master into ToMapAndToMultimap
Merge branch 'ToMapAndToMultimap' of github.com:akarnokd/RxJava into pull-513-toMap

Conflicts:
	rxjava-core/src/main/java/rx/Observable.java
Merge pull request #526 from benjchristensen/pull-513-toMap

Manual Merge of toMap/toMultiMap