FMod - v2.8.1

I finished up testing the changes to level management and the Flood Filler today. Everything seems to be in order; all actions are easily undoable. I only made one change: all the fillers (rectangle, circle, flood) now allow selecting the tiles under the cursor by right-clicking. That way, you don't have to switch to the Tile Placer if you change your mind about what tiles you want to fill with.

I released the changes from these last few days as v2.8.1.