* Future-proof some Guava usage
* Use a java-util EmptyIterator instead of Guava's
* Change some of the guava future handling to do manual async
transforms. Guava changes transform into transformAsync by deprecating
transform in ONLY Guava 19. Then its gone in 20
* Use `Collections.emptyIterator()`
* Pretty formatting
* Make listenable future transforms a thing in default druid
* Format fix
* Add forbidden guava apis
* Make the ListenableFutrues.transformAsync have comments
* Undo intellij bad pattern matching in comments
* Futrues --> Futures
* Add empty iterators forbidding
* Fix extra `A`
* Correct method signature
* Address review comments
* Finish Gian review comments
* Proper syntax from https://github.com/policeman-tools/forbidden-apis/wiki/SignaturesSyntax