Release framework object ASAP to reduce memory consumption

This release resolves memory consumption issues caused by the retention of framework objects collected during the course of test execution. While implementing these revisions, I discovered and resolved a few fundamental issues in the handling of parameterized tests as well.

Resolving these fundamental issues required me to revise a few public interfaces, which informed the major-version bump.

• The AtomicTest class is no longer parameterized.
• The RunWatcher interface is no longer parameterized.
• The LifecycleHooks class now provides target => atomic test mappings.
• The LifecycleHooks class now provides description => atomic test mappings.
• The LifecycleHooks class no longer publishes runner <=> target mappings.
• The signature of the TestObjectWatcher.testObjectCreated() interface method has changed.