preparations for re-writing godmode
Revert "removed one more redundant event handler"

This reverts commit ce89b5c94853d810b57e35714efb141cbfef4858.
Revert "Removed redundant damage-related event handlers"

This reverts commit ec83ef3ba095183083435dc1628507c50a01a4ca.
re-implemented god mode by adding more listeners, and minor formatting
mobs no longer target unauthenticated players
added anti-drowning, removed night vision potion effect

Otherwise, a legitimate night vision potion effect might be removed by
the plugin