Merge pull request #1 from samuelgruetter/RxJavaBugFixesSam

A few trivial Scala adaptor details
Pulled in changes from Samuel.
Fixed tests, all working without warnings
Added Observable.create.
(a) it will stop the pointless discussions around it.
(b) it is removes the interference with from(T*)
(c) we should remove the latter, since that is not the common case.
Double negation Observer.
Made subjects safe
Trivial code movements
IntelliJ suggested style changes.
undo commit 99a1d035233100e32050240472a9bdc85521bc61