Operator: Generate

[benjchristensen]

http://msdn.microsoft.com/en-us/library/hh229642(v=vs.103).aspx
http://msdn.microsoft.com/en-us/library/hh229270(v=vs.103).aspx
http://msdn.microsoft.com/en-us/library/hh212066(v=vs.103).aspx
http://msdn.microsoft.com/en-us/library/hh212014(v=vs.103).aspx
http://msdn.microsoft.com/en-us/library/hh244290(v=vs.103).aspx
http://msdn.microsoft.com/en-us/library/hh211794(v=vs.103).aspx

[benjchristensen]

As per @headinthebox this is really only used in demos and super complicated and thus should not be added to RxJava.

Anything that can be done via generate should instead be done inside Observable.create(OnSubscribeFunc f) optionally with a `Scheduler.