Update Observable.java

standardizing javadoc comments & adding wiki/image links for new methods
Operations toMap (3) and toMultimap (4)
Merge upstream/master into ToMapAndToMultimap
UnitTests demonstrating bugs
BugFix: Handling of Terminal State for Behavior/Publish Subjects

- They were not correctly emitting onCompleted when new Observers subscribed after the Subject was terminated.
- Added same logic that already existed on AsyncSubject
Merge pull request #525 from benjchristensen/bugfix-subjects

BugFix: Handling of Terminal State for Behavior/Publish Subjects
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
Javadoc improvements, including diagrams and wiki links for new operators
Update Observable.java

improve javadocs, including diagrams and wiki links for new operators
Missing ! .... grrr.
Fix bad unit test

- no further events expected after unsubscribe
Calling constructor explicitly on schedulers
Notification constructors
Implicit conversions
Add License Headers
Merge pull request #529 from benjchristensen/scala-tweaks

Scala Tweaks
Merge pull request #527 from Netflix/docs

Docs
[Gradle Release Plugin] - pre tag commit:  '0.15.1'.
[Gradle Release Plugin] - new version commit:  '0.15.2-SNAPSHOT'.
Version 0.15.1