Release notes edits.
Release notes edits.

samuelgruetter/RxScala,samuelgruetter/RxScala,jbripley/RxScala,TracyLu/RxScala,zjrstar/RxScala,ReactiveX/RxScala,hermanbanken/RxScala,joohnnie/RxScala,zhongdj/RxScala,hermanbanken/RxScala,jbripley/RxScala