More Lua Functions and editor stuff

-Removed Some non-essential invokes in CoreEngine
-Added Generate Random button for editor
-Added PlayerManager.allowTimedRespawn to allow more flexible respawn
system
-PlayerManager.respawnAll() now  resets
-Fixed bug where TerrainLayer.generateRandom() and generateIsland() not
rendering if used on already rendered cell
-Added TerrainWrapper.generateRandom() and generateIsland()