Khimera version 2.8

Another small update today. We've rolled back to the previous music engine as the new one was causing slowdown on some systems.

Also shout-out to that one guy who really likes using Megaman X's OST with Khimera because you can do that again.

Version 2.8 - December 12, 2017

• Rollback to previous music engine (pre-2.6).
• Various dialogue fixes.
• Minor updates to map and victory screen UIs.