Add multi-world support

[macarooni-man]

Currently, auto-mcs doesn't have the ability to manage multi-world servers internally.

• Add a horizontal storyline menu (like a basic video editor timeline) that allows you to add multiple worlds, and re-arrange their internal ID's
• Add a checkbox to enable multi-world:
  • When off, just make it switch the worlds out in the server.properties and the folder
  • When turned on, verify that the server supports multi-world by type and add-ons