[Survival] Upgraded to mcMMO Overhaul

[Towelie]

Survival was upgraded to use the new mcMMO Overhaul.
You should notice a lot of changes in mcMMO, and a lot of bugfixes as well.

Changelog: https://www.mcmmo.org/#changelog

NOTE: Due to the massive changes, there may be some things that work differently. Please read everything about the mcMMO overhaul here https://www.spigotmc.org/resources/official-mcmmo-overhaul.64348/

NOTE: XP gaining has been reduced even further to prepare for the boost of the max level cap to 1000 in 1.14