Added a new glow toggle feature with /itf toggle glow [glow color] and /itf togglemode glow [glow color]. This allows you to give item frames a glow color. The permissions are:
invisibleitemframes.command.toggle.glow
invisibleitemframes.command.togglemode.glow
Changed /itf toggle and /itf togglemode to /itf toggle visibility and /itf togglemode visibility.
Changed the permissions used for the visibility toggle to work with multiple toggle types: