Request Up When Dropping Values
ObserveOn Cleanup

- make code easier to understand with some refactoring of the pollQueue loop
- add a unit test to ensure correct behavior with a hot Observable source
ObserveOn Error Propagation

- errors were not being propagated if backpressure was exerted (requested==0)
- terminal events do not need to be requested so it now ignores the requested count to emit onError
Merge pull request #1728 from benjchristensen/observeOnErrorPropagation

ObserveOn Error Propagation
Merge pull request #1729 from benjchristensen/combineLatest-1717

CombineLatest: Request Up When Dropping Values
Remove Unused Code
Merge pull request #1731 from benjchristensen/issue-1525

Remove Unused Code
Add dates
Version 1.0.0-rc.5
Move To Proper Location

Was accidentally committed in old rxjava-core src folder.
Merge pull request #1733 from benjchristensen/clean-stray-file

Move To Proper Location
Update README.md
javadoc changes to correspond with recent method changes
more javadoc changes to correspond with recent method changes
Fix TrampolineScheduler NullPointerException

I tried for about 30 minutes to replicate the NPE reported in https://github.com/ReactiveX/RxJava/issues/1702 but couldn't.
It makes sense reading the code that an unsubscribe could trigger an NPE though so I'm fixing it as per recommendation of @DylanSale even though I can't replicate.
I confirmed that the items are being put in the queue BEFORE the wip variable is incremented, so that concurrency seems okay.
Remove use of ThreadLocal

This was an awkward leftover from early version of RxJava (pre v0.17).
Delay Operator with Reactive Pull Backpressure

Updated the implementations to support reactive pull backpressure.
Fixes https://github.com/ReactiveX/RxJava/issues/1724
Fix Slow Non-deterministic Test

Somehow I missed the Thread.sleep to force the scenario so most of the time this test would run very slow (or forever).
I'm surprised the unit tests passed before... just random luck on thread scheduling.
Merge pull request #1739 from benjchristensen/observeOn-testErrorPropagatesWhenNoOutstandingRequests

Fix Slow Non-deterministic Test
Merge pull request #1738 from benjchristensen/issue-1724

Delay Operator with Reactive Pull Backpressure