Implemented the 'SkipLast' operator
Updated the comments
Fixed the issue about null values
Optimize for 'count == 0'
add exists and isEmpty
TestScheduler example
make all constructors private
update TODO
Implemented the 'Empty' operator with scheduler
Added MSDN links
Added missing license header
allow to construct Observables ina similar way as futures
implicit function conversion hack just for nicer scaladoc
make defer implementation more explicit
apply review patch
head, headOrElse, zip(3), zip(4)
changes from review + scaladoc improvements
improve scaladoc
rename fold to foldLeft
remove takeWhileWithIndex