Merge pull request #709 from Netflix/docs

Lotsa javadoc improvements
Merge pull request #710 from Netflix/docs

Created new wiki page for the operators in the Async class
Update Scheduler Tests for Recursion and Common Testing
Fix Deprecated Method Call
Memory Leak Tests

NewThreadScheduler is working, the other two are not so commented out for now until fixed.
Fix Memory Leak in NewThreadScheduler Recursion

- the Action0 method did not have a leak
- the Func2 method on inner scheduler recursion did have a leak
Scheduler Unit Tests

- passing for all but ExecutorScheduler
ExecutorScheduler Memory Leak Fix

- new InnerExecutorScheduler and childSubscription
- improvements to unit tests
CurrentThreadScheduler Memory Leak Fixed

- Current/Immediate/NewThread/Executor Schedulers are passing unit tests
- Current/NewThread/Executor Schedulers do not leak memory on the recursion test (Immediate can’t be used for recursion otherwise it stack overflows)
Small ObserveOn Improvements

- use Long instead of Int so we don’t overflow
- migrate from deprecated method
CurrentThreadScheduler Fixes

- outer/inner scheduling so nested order is correct while not deadlocking on certain nested use cases as found in previous testing
Fix CurrentThreadScheduler Delay Bug

- introduced a bug during refactor, caught it while updating unit tests
Updated Schedulers Unit Tests

- merged all scheduler tests into the same package
- using inheritance so that the same tests are applied to each of the different Scheduler implementations
- manual test (too slow for normal execution) can be run to test memory leaks (TestRecursionMemoryUsage.java)
Missing Header
Increasing Unit Test Timeout for Slow Machines

- Increasing timeout by a lot to handle slow machines such as this: https://netflixoss.ci.cloudbees.com/job/RxJava-pull-requests/629/testReport/junit/rx.schedulers/ExecutorSchedulerTests/recursionUsingFunc2/
- The timeout is only there if a deadlock or memory leak occurs (which is what this PR is fixing) so when everything is healthy it does not timeout
Remove Timeout on Tests
Remove Validation of Ordering

- this test does a flatMap which uses merge which has non-deterministic ordering since the Observable.from can be on a new thread each time
Merge pull request #712 from benjchristensen/scheduler-memory-leak

Fix Scheduler Memory Leaks
rxjava-computation-expressions

The conditional operators are going in this contrib module.

See https://github.com/Netflix/RxJava/issues/683
Merge pull request #714 from benjchristensen/rxjava-computation-expressions

rxjava-computation-expressions