* try to load unqualified plugins from whitelist
* necessary for backcompat loading of unqualified collectionized callback plugins redirected from <= 2.9 core
* also added de-duping from actual loaded name
* add tests
* add warning test
* group test script entries by topic
* shorten warning text grep because wrapping is dumb
* fix adhoc callback loading behavior
* collections pass over whitelist wasn't respecting `_run_additional_callbacks`
* adds regression tests for same
* avoid `grep -L` in tests since it breaks the world
