Merge pull request #536 from NQNStudios:recast-hint

Quality of life: Spellcasting

This makes changes to the spellcasting UI.

* M or P to recast will no longer default to Light or Minor Bless/Minor Heal. You need to cast something before recast becomes available. This fixes #535 and I think it's disorienting when I've just started the game and M casts Light in a town that's fully lit, so the change is generally good I'd say.
* I implemented a recasting hint in the text bar, which was one of the things I mentioned in my quality-of-life checklist https://github.com/NQNStudios/cboe/issues/16. It replaces the status icons in combat mode.
* Sometimes when my eyes glaze over, I think I'm casting the spell on the wrong side of the LED. I thought there was a bug when I cast Long Light instead of Dumbfound (even though I know the distance between the two is pretty large -- I wasn't paying much attention). I thought it would be nice to highlight the name of the selected spell. Light green seemed to make more sense than red for that, because the LED turns green. Then I made the caster/target selection texts also use light green instead of red, to match. Uncastable spells are grey.

src/game/boe.main.cpp

@@ -147,7 +147,7 @@ eStatMode stat_screen_mode;
 short anim_step = -1;
 
 // Spell casting globals
-eSpell store_mage = eSpell::LIGHT, store_priest = eSpell::BLESS_MINOR;
+eSpell store_mage = eSpell::NONE, store_priest = eSpell::NONE;
 short store_mage_lev = 0, store_priest_lev = 0;
 short store_spell_target = 6,pc_casting;
 short num_targets_left = 0;