Second Update - Visual Updates, Tweaks, and Bug Fixes

I've uploaded another batch of small updates, tweaks and fixes. Here's an overview of the recent changes:

• Add an option to go fullscreen in settings. This sounds like a no-brainer, but I had completely forgotten about it, mainly because I use a tiling window manager (StumpWM) and, well, I'm always fullscreen! So it only recently came to my mind that maybe I should check how things look with a normal window manger. Sorry windowed people!
• I've added some plants and trees to the planet. You will of course destroy these when building over them. Nothing in the way of progress.
• Instead of having a big black box around the selected building, we now have a nice outline.
• Add an option to start a new game. This is available in the settings menu, and also in the "the end" screen.
• Some more bug fixes.

And that's about it.