v0.0.6

This release contains important fixes and improvements to stability and performance, including:

• Fix backoff-retry with deadline and timeout behaviour in KVClient requests
  • Deadline encompasses all retries (if specified), timeout applies to each attempt
• Retry DNS resolution errors
• Ensure internal threads are shutdown cleanly when closing clients
• Use dedicated unbounded executor as default for callbacks instead of common ForkJoinPool
• Streamline KVClient sync() requests and RangeCache method threading

Custom executors can now be specified per call for KVClient async requests (via the new .executor(Executor) builder method).