Add cache(int capacity) to Observable
Revert "CompositeException does not mutate nested exceptions by attaching stacks, but instead"

This reverts commit f4ae92aa624923e9a632fb677730a2d6e04595e5.
Remove cycles in CompositeException
Move cast to parent function
Remove cast
Remove unused imports/locals
Add generics
Add generics
Correct static access warnings
[Gradle Release Plugin] - pre tag commit:  '0.20.0-RC1'.
[Gradle Release Plugin] - new version commit:  '0.20.0-RC2-SNAPSHOT'.
Version 0.20.0-RC1
first pass at javadocs for new backpressure stuff
Zip with Backpressure Support

This supports both upstream and downstream backpressure.
RxScala: Add Scala idiomatic methods
Merge pull request #1448 from zsxwing/rxscala-more

RxScala: Add Scala idiomatic methods
New test case for takeWhile that currently fails
Fix issue #1451
Fix related classes for issue #1451
OperatorAll & Backpressure

Similar to filter, it needs to request(1) each time it filters an onNext.