Nether Islands!

[prosavage]

Implemented Nether Island Dimensions

• Portals redirect to skyblock nether world.
• New Island structure file comes bundled in SkyblockX.jar.
• Nether Island is automatically generated on demand (First time entering nether portal on island).
• WorldBorder packet is sent in context to Nether Island to show borders.
• Block, Mob, and Interact protection listeners updated to work inside of the nether world.
• Nether World is generated on startup like the SkyblockX overworld is.
• Updated Island Type Config option with property for nether structure file.