Implemented SPA 483

Implemented
Fc_Spell_Damage_Pct_IncomingPC	483
- Focus effect that modifies iby percent incoming spell damage on the target.
Base1= min Base2= max. Final percent is random between max and min each time focus is applied from a spell cast.

Note: Written to stack with similar functioning focus SPA 269 SE_FcSpellVulnerability.

zone/common.h

@@ -124,6 +124,7 @@ typedef enum {	//focus types
 	focusSpellHateMod,
 	focusTriggerOnCast,
 	focusSpellVulnerability,
+	focusFcSpellDamagePctIncomingPC,
 	focusTwincast,
 	focusSympatheticProc,
 	focusFcDamageAmt,