Consider replacing sprite type buttons with sprite flags

[gabrielflorit]

we might need more than just 4 kinds of sprites

[Kethku]

Some documentation about the fact that those are sprite types would be useful (maybe I missed it?) I had no idea that was what those buttons were for.

[colxi]

I agree. 4 sprite types is a little short. In a game with basic physics support (gravity and wall collision), normally you end with only 2 sprite types left, because the other 2 are needed to flag the floor and wall sprites.

Just having 8 instead of 4, would suppose a big change.

[icarito]

Not very clear how this works in the first place. +1 for making it more discoverable / flexible