Lightmap is applied to items and text in GUIs

Items and text rendered in GUIs (e.g. inventories, pause screen, title screen) are tinted according to the world light map. Text in chat is affected as well. The tint also flickers as block light flickers in-game. This is barely noticeable with the vanilla light map because block light is white and does not flicker very much, but it is still noticeable if one looks carefully.