Clean up old (and partially unused) Aggro() function and use EnterCombat() instead + fix some minor enum-typos (INTURRUPT -> INTERRUPT)

(fix by Azazel)

--HG--
branch : trunk

src/server/scripts/EasternKingdoms/AlteracValley/boss_drekthar.cpp

@@ -62,7 +62,7 @@ struct boss_drektharAI : public ScriptedAI
         uiYellTimer = urand(20*IN_MILLISECONDS,30*IN_MILLISECONDS); //20 to 30 seconds
     }
 
-    void Aggro(Unit * /*who*/)
+    void EnterCombat(Unit * /*who*/)
     {
         DoScriptText(YELL_AGGRO, me);
     }

src/server/scripts/EasternKingdoms/AlteracValley/boss_galvangar.cpp

@@ -55,7 +55,7 @@ struct boss_galvangarAI : public ScriptedAI
         uiResetTimer                      = 5*IN_MILLISECONDS;
     }
 
-    void Aggro(Unit * /*who*/)
+    void EnterCombat(Unit * /*who*/)
     {
         DoScriptText(YELL_AGGRO, me);
     }

src/server/scripts/EasternKingdoms/AlteracValley/boss_vanndar.cpp

@@ -60,7 +60,7 @@ struct boss_vanndarAI : public ScriptedAI
         uiYellTimer = urand(20*IN_MILLISECONDS,30*IN_MILLISECONDS);
     }
 
-    void Aggro(Unit * /*who*/)
+    void EnterCombat(Unit * /*who*/)
     {
         DoScriptText(YELL_AGGRO, me);
     }