Revert "Don't naturally let extensions overwrite core functions and events."

This reverts commit 01d47750ff7dc6866d9f2cd12210c99f15639b33.
Revert most of 94489525e2680f471d14adc9cd7d5462aaea661b
"Experimentation with capture_runas to make it more resilient."
Merge conflict exception:  src/main/java/com/laytonsmith/tools/docgen/DocGenUI.java

This fixes 2938 until it can be properly resolved.