Each state now has an OnOpen and OnClose callback function. These are available to be set by the client but not required. If not set, they will be ignored.
There is no "lmeta" and "rmeta" constants I can find in Love2D (https://love2d.org/wiki/KeyConstant) and the check for those keys caused the gui to crash on MacOS. Simply checking for lgui and rgui is enough for MacOS Command key.
