[DEV] Environment Visual Improvements

Hey Dungeoneers,

Work on Shattered Pixel Dungeon v4.0.0 continues! I expect I'll be making a blog post about what's coming sometime in the next week or so, though unfortunately I don't yet have an ETA for when the update will be ready for beta testing.

A big part of why it's taken so long is that v4.0 has become a bigger update than initially planned. I'll be sharing some more details on this soon, but here's a little teaser in the meantime. A bunch of improvements are coming to visuals in the dungeon environment, and this includes some improvements to the upcoming vault quest before it even releases!