Making the editor function

[njd5475]

In addition the commits include a lot of additional changes so take it however you want.

[Shoozza]

Hi, sorry for the late reply.

I'll have to split this up into multiple things.
E.g the LÖVE 11 port could be a separate pull request.

Thanks for the contribution :)

[Shoozza]

On further inspection, this crashes on the "ls" command after it starts scrolling:

LOVE - Warning: api.lua:258: Using deprecated function love.filesystem.isDirectory (replaced by love.filesystem.getInfo)
Error: api.lua:283: love.event.wait cannot be called while a Canvas is active in love.graphics.
stack traceback:
        [love "boot.lua"]:345: in function <[love "boot.lua"]:341>
        [C]: in function 'wait'
        api.lua:283: in function 'ls'
        [string "nocart.p8"]:178: in function <[string "nocart.p8"]:54>
        main.lua:1027: in function <main.lua:988>
        [C]: in function 'xpcall'
        [love "boot.lua"]:361: in function <[love "boot.lua"]:348>
        [C]: in function 'xpcall'