improve switchOnNext description in javadocs
repair anchors in links to RxJava wiki in javadocs
Observer+Subscription -> Subscriber
Subscriber and Observer

-> Restore Observer interface
-> Subscriber implements Observer, Subscription
Merge pull request #791 from Netflix/docs

improve switchOnNext description in javadocs
Subject reverted to Observable+Observer

- rxjava-core is passing all unit tests
- other modules are failing
working on stuff
Restored use of Observer in most places
Fix Scala Build
Merge pull request #793 from benjchristensen/subscriber-observer

Observer + Subscriber