Changes

• Support ackWait #73 @tilakraj94
• Tuning and Tests #74 @scottf

Version Note Regarding 2.1.4 and 2.2.0

There was technically a violation of semver. An api that was renamed in 2.1.4 should only have been deprecated.
2.2.0 fixes this by changing the name back.

In JetStreamSubjectConfiguration.Builder, ackMode() was incorrectly renamed to ackBehavior()

This has been "fixed" as in

Bob Slydell: "We, uh, we fixed the glitch. So he won't be receiving a paycheck anymore, so it'll just work itself out naturally."

Very sorry, we appreciate your understanding, at least we didn't steal your stapler.