World Downloader 1.7.10c beta #2 for Minecraft 1.7.10

Recommended bugfix update; also should greatly improve performance when saving.

• Language fixes
• Major performance improvements when saving, particularly in chunks with a lot of entities or tile entities
  • Fixed crashes in chunks with lots of entities or tile entities
• Fixed a crash that happened when saving starts
• Added dimension info in the multiworld select GUI (will be expanded upon)
• Fixed overwriting single player worlds if the server has the same name
• Allowed enabling/disabling individual extensions
• Moved entity realignment code to a (included by default) extension
• Fixed a crash involving the profiler and plugin messages
• Fixed a crash when the open GUI doesn't match the looked at TE with some blocks (eg furnaces)
• Fixed game freezing that happened when permissions changed on a dimension change
• Partial creation of the chunk overrides request GUI (not finished)