1.5.4 - New World File "Sofu" + some fixes

This update adds a new world file, "Sofu", and also fixes a bug relating to destroying transports.

Because there are now more than 4 world files, you'll need to scroll down to see it when you create a new game.

For Sofu, I cranked the world size up one level, so this might have more systems to explore than the other world files so far. Funny story, I tried cranking the difficulty up one level, but when I warped into a planet there were ships just auto-destructing everywhere-- this was a nice way to net infinite experience but generally speaking it broke the game badly. I'm not sure why this happened!

Progress is going on in the background to update the rendering engine-- this is actually going really well, but the way I did it was flagged it to only render this way in the development build. This is important because I'm not planning (at all) to try and match the current visual style, instead the current shaders are basically a "stub" to give me a starting point. So you won't see any change (at all) with this or the next bunch of updates, that's why I'm just adding new world files.

Redoing the core rendering this way was surprisingly easy, so I have the core rendering code moved over to shaders for 90% of the stuff that's there (basically, everything except effects such as clouds or lightning.) The next problem will be figuring out how to revamp the visuals without needing to affect too strongly the other parts of the game.

There is a blog post on the Kitty Lambda website that talks a bit about it, along with some glitch screenshots: https://kittylambda.com/?p=dev_blog_2020-08-08_vtv_shader_work