Added: Option to heal players at the start of waves or bosses.

Added: Option for classes to require a specific permission, in order to ready up as the class.
Allows players to preview classes, without being able to use them.

Added: Option to show "mobs-left" on the actionbar, instead of the chat.

Changed: Messages sent in chat now have the prefix defined in MobArena's config file.

Fixed: Some minor config stuff regarding things under development.