rangecheck: rewrite of the 40y range check

* remove the bad notice in GUI
* set default interval to "2"
* prevent all frames of being updated at once
* refresh one unit after the other
* use textures insted of spellnames
* change interval settings to dropdown
* remove no longer required locales

env/locales_enUS.lua

@@ -26,13 +26,6 @@ pfUI_locale["enUS"]["itemtypes"] = {
   ["INVTYPE_PROJECTILE"] = "Projectile",
 }
 
-pfUI_locale["enUS"]["rangecheck"] = {
-  ["PALADIN"] = "Holy Light",
-  ["PRIEST"] = "Flash Heal",
-  ["DRUID"] = "Healing Touch",
-  ["SHAMAN"] = "Healing Wave",
-}
-
 pfUI_locale["enUS"]["hunterpaging"] = {
   ["MELEE"] = "Wing Clip",
   ["RANGED"] = "Arcane Shot",