INT-3354 Fix Priority Order in RedisPCMS

JIRA: https://jira.spring.io/browse/INT-3354

Wrong sort order; was treating priority 0 as highest.
INT-2595: Add Time-Based `ReleaseStrategy` Option

JIRA: https://jira.spring.io/browse/INT-2595

* Add `group-timeout` and `group-timeout-expression` to the Correlation Endpoint
* Add logic to the `AbstractCorrelatingMessageHandler` to schedule group for `forceComplete`,
when the target `ReleaseStrategy` returns `false`

INT-2595: Polishing according PR comments

INT-2595: Expose `lock-registry` and further docs

INT-2595 Doc and Test Polishing

INT-2595: Fix typos

INT-2595 More Minor Doc Polish
INT-3352 RedisLockRegistry

JIRA: https://jira.spring.io/browse/INT-3352

Provid a global lock registry, initially for the correlating
message handlers.
INT-3252 Polishing

- Use a discrete key for each lock and use Redis EXPIRE
- Use an internal DefaultLockRegistry to improve latency
    when threads are using the same registry instance.
INT-3352 More Polish

- Put localLock.unlock() in a finally block.
- Unlock localLock if acquiring the RedisLock fails.
INT-3352 Polishing - PR Comments

- PR Comments
- Improve equals()
INT-3352 Add Aggregator Integration Test

- move lock registry to the `util` package
- Add an aggregator integration test