Change Lift to use rx.Observable.Operator

The generics insanity has to stop.
Merge pull request #857 from benjchristensen/operator-type

Change Lift to use rx.Observable.Operator
Add 'Fragment-Host' to rxjava-contrib/debug module for OSGi
Merge pull request #859 from Acardiac/fragment-host

Add 'Fragment-Host' to rxjava-contrib/debug module for OSGi