Created test cases that show inconsistent error handling with OnNextValue and toString
Fixed OnNextValue to not call toString on the failing value
Use currying to improve type inference
Rename to sliding and tumbling
Added a renderValue function to create a string from unknown client objects without calling toString (PR #1401)
Merge pull request #1401 from samhendley/onnextvalue

OnError while emitting onNext value: object.toString
0.19.4-SNAPSHOT

Manually incrementing as the upload to Maven Central for 0.19.3 failed part way through and can't be redone.
[Gradle Release Plugin] - pre tag commit:  '0.19.4'.
[Gradle Release Plugin] - new version commit:  '0.19.5-SNAPSHOT'.
Version 0.19.4
Backpressure & 0.20.0-RC1
Merge pull request #1412 from benjchristensen/backpressure-9

Backpressure & 0.20.0-RC1
Fix Merge Bug

If the queue being drained did not complete due to the backpressure request being fulfilled, it could onComplete before draining the queue and miss values.
Clarity about batching request
Test timing

Adjust timing for slower machines (such as CloudBees)
Merge pull request #1414 from benjchristensen/merge-fixes

Merge Fixes
Merge pull request #1398 from zsxwing/rxscala-currying

RxScala: Use currying to improve type inference