- add spotbugs-maven-plugin
- use spotbugs-annotations instead of jsr305

- protect for NPE in method isAutoWrapper
    - add UT for getting unboxing boolean from map
- rename method/var: setAutoWrapper -> setAutoWrapperAttachment

unwrap ttl runnable for before/afterExecute methods
of executor subclass when decorate by ttl agent

- setAutoWrapper for TtlRunnable/TtlCallable
  in TtlExecutorTransformlet(Agent)
- update before/afterExecute methods of executor subclasses,
  unwrap runnable if isAutoWrapper

should unwrap ttl runnable for before/afterExecute methods of executor subclass
when decorate by ttl agent

https://github.com/JetBrains/kotlin/releases/tag/v1.3.10