Intended to make KI text (player list and chat) better readable on light and patterned backgrounds. In this WIP, all text on GUI controls is rendered shadowed.
This fixes the irregular dark fringes around light text when not exactly pixel-aligned that are caused by independent interpolation of color and alpha. It also makes calculations simpler for things to come.
In addition to being a prerequisite for shadowed text, this also fixes an issue sometimes seen at the bottom of the mini KI player list where characters with a descender were missing.