Fix unicode character support in VGUI/HUD elements

 * The "custom" "1" font flag breaks things and doesn't seem to be necessary, but I'm not totally sure what it's for (see https://developer.valvesoftware.com/wiki/Authoring_and_Using_TrueType_Fonts#The_.22Scheme.22)
 * Fixes fortressforever/fortressforever#19