v0.2.1: New level + level editor improvements

• New level: Roundabout: There's a new (easy) level to play! :D
• Refurbished level editor: You can now edit level metadata in the level editor without having to export it first. You can also choose between rectangular or circular shaped walls now (see the new level)!
• UI improvements: The behavior and visual effects of the UI around the level editor and menus have largely been improved, particularly in Firefox.

And tons of bug fixes:

• No more lag in singleplayer: I've totally eliminated lag from singleplayer rooms. Your little dot should not twitch at all, even if you have high ping! I haven't tested how this affects multiplayer, but I'd imagine multiplayer rooms have also improved. This is the result of countless hours testing and tweaking.
• Probably fixed Times New Roman showing up?
• Fixed repeated playtesting causing the game to crash
• Fixed messages from server being processed out of order, causing yet more crashes
• Attempted fix for bug where rooms can't be created after logging in
• Fixed bug where adding a new portal in the level editor and changing its color causes multiple portals to change color
• Various internal fixes