Core/Spells: spell effect handling improvements

* Call spell effect handlers in 4 modes:
   - SPELL_EFFECT_HANDLE_LAUNCH - called when spell is launched (cast just finished)
   - SPELL_EFFECT_HANDLE_LAUNCH_TARGET - called when spell is launched for each target in spell target map
   - SPELL_EFFECT_HANDLE_HIT - called when spell hits its destination
   - SPELL_EFFECT_HANDLE_HIT_TARGET - called when spell hits it's target from spell target map
*Correctly implement SPELL_EFFECT_TRIGGER_SPELL, SPELL_EFFECT_TRIGGER_SPELL_WITH_VALUE, SPELL_EFFECT_TRIGGER_MISSILE_SPELL_WITH_VALUE, SPELL_EFFECT_TRIGGER_MISSILE_SPELL
*Remove spell system hacks which became obsolete with this commit
Core/SpellScripts:
add OnEffectLaunch, OnEffectLaunchTarget, OnEffectHit, OnEffectHitTarget hooks for new effect handle modes and remove OnEffect hook.
A generic rule of thumb how to update your scripts (will work for nearly all cases) for spell system noobs:
if your spell script used GetHitXXXX function, you need to use OnEffectHitTarget, otherwise use
OnEffectHit

src/server/scripts/Spells/spell_item.cpp

@@ -57,7 +57,7 @@ public:
 
         void Register()
         {
-            OnEffect += SpellEffectFn(spell_item_trigger_spell_SpellScript::HandleDummy, EFFECT_0, SPELL_EFFECT_DUMMY);
+            OnEffectHit += SpellEffectFn(spell_item_trigger_spell_SpellScript::HandleDummy, EFFECT_0, SPELL_EFFECT_DUMMY);
         }
     };
 
@@ -107,7 +107,7 @@ public:
 
         void Register()
         {
-            OnEffect += SpellEffectFn(spell_item_deviate_fish_SpellScript::HandleDummy, EFFECT_0, SPELL_EFFECT_DUMMY);
+            OnEffectHit += SpellEffectFn(spell_item_deviate_fish_SpellScript::HandleDummy, EFFECT_0, SPELL_EFFECT_DUMMY);
         }
     };
 
@@ -184,7 +184,7 @@ public:
 
         void Register()
         {
-            OnEffect += SpellEffectFn(spell_item_flask_of_the_north_SpellScript::HandleDummy, EFFECT_0, SPELL_EFFECT_DUMMY);
+            OnEffectHit += SpellEffectFn(spell_item_flask_of_the_north_SpellScript::HandleDummy, EFFECT_0, SPELL_EFFECT_DUMMY);
         }
     };
 
@@ -234,7 +234,7 @@ public:
 
         void Register()
         {
-            OnEffect += SpellEffectFn(spell_item_gnomish_death_ray_SpellScript::HandleDummy, EFFECT_0, SPELL_EFFECT_DUMMY);
+            OnEffectHitTarget += SpellEffectFn(spell_item_gnomish_death_ray_SpellScript::HandleDummy, EFFECT_0, SPELL_EFFECT_DUMMY);
         }
     };
 
@@ -298,7 +298,7 @@ public:
 
         void Register()
         {
-            OnEffect += SpellEffectFn(spell_item_make_a_wish_SpellScript::HandleDummy, EFFECT_0, SPELL_EFFECT_DUMMY);
+            OnEffectHit += SpellEffectFn(spell_item_make_a_wish_SpellScript::HandleDummy, EFFECT_0, SPELL_EFFECT_DUMMY);
         }
     };
 
@@ -353,7 +353,7 @@ public:
 
         void Register()
         {
-            OnEffect += SpellEffectFn(spell_item_mingos_fortune_generator_SpellScript::HandleDummy, EFFECT_0, SPELL_EFFECT_DUMMY);
+            OnEffectHit += SpellEffectFn(spell_item_mingos_fortune_generator_SpellScript::HandleDummy, EFFECT_0, SPELL_EFFECT_DUMMY);
         }
     };
 
@@ -409,7 +409,7 @@ public:
 
         void Register()
         {
-            OnEffect += SpellEffectFn(spell_item_net_o_matic_SpellScript::HandleDummy, EFFECT_0, SPELL_EFFECT_DUMMY);
+            OnEffectHitTarget += SpellEffectFn(spell_item_net_o_matic_SpellScript::HandleDummy, EFFECT_0, SPELL_EFFECT_DUMMY);
         }
     };
 
@@ -466,7 +466,7 @@ public:
 
         void Register()
         {
-            OnEffect += SpellEffectFn(spell_item_noggenfogger_elixir_SpellScript::HandleDummy, EFFECT_0, SPELL_EFFECT_DUMMY);
+            OnEffectHit += SpellEffectFn(spell_item_noggenfogger_elixir_SpellScript::HandleDummy, EFFECT_0, SPELL_EFFECT_DUMMY);
         }
     };
 
@@ -522,7 +522,7 @@ public:
 
         void Register()
         {
-            OnEffect += SpellEffectFn(spell_item_savory_deviate_delight_SpellScript::HandleDummy, EFFECT_0, SPELL_EFFECT_DUMMY);
+            OnEffectHit += SpellEffectFn(spell_item_savory_deviate_delight_SpellScript::HandleDummy, EFFECT_0, SPELL_EFFECT_DUMMY);
         }
     };
 
@@ -604,7 +604,7 @@ public:
 
         void Register()
         {
-            OnEffect += SpellEffectFn(spell_item_six_demon_bag_SpellScript::HandleDummy, EFFECT_0, SPELL_EFFECT_DUMMY);
+            OnEffectHitTarget += SpellEffectFn(spell_item_six_demon_bag_SpellScript::HandleDummy, EFFECT_0, SPELL_EFFECT_DUMMY);
         }
     };
 
@@ -660,7 +660,7 @@ public:
 
         void Register()
         {
-            OnEffect += SpellEffectFn(spell_item_underbelly_elixir_SpellScript::HandleDummy, EFFECT_0, SPELL_EFFECT_DUMMY);
+            OnEffectHit += SpellEffectFn(spell_item_underbelly_elixir_SpellScript::HandleDummy, EFFECT_0, SPELL_EFFECT_DUMMY);
         }
     };
 
@@ -784,7 +784,7 @@ class spell_item_red_rider_air_rifle : public SpellScriptLoader
 
             void Register()
             {
-                OnEffect += SpellEffectFn(spell_item_red_rider_air_rifle_SpellScript::HandleScript, EFFECT_0, SPELL_EFFECT_SCRIPT_EFFECT);
+                OnEffectHitTarget += SpellEffectFn(spell_item_red_rider_air_rifle_SpellScript::HandleScript, EFFECT_0, SPELL_EFFECT_SCRIPT_EFFECT);
             }
         };
 
@@ -838,7 +838,7 @@ class spell_item_create_heart_candy : public SpellScriptLoader
 
             void Register()
             {
-                OnEffect += SpellEffectFn(spell_item_create_heart_candy_SpellScript::HandleScript, EFFECT_0, SPELL_EFFECT_SCRIPT_EFFECT);
+                OnEffectHitTarget += SpellEffectFn(spell_item_create_heart_candy_SpellScript::HandleScript, EFFECT_0, SPELL_EFFECT_SCRIPT_EFFECT);
             }
         };
 
@@ -995,7 +995,7 @@ class spell_item_vanquished_clutches : public SpellScriptLoader
 
             void Register()
             {
-                OnEffect += SpellEffectFn(spell_item_vanquished_clutches_SpellScript::HandleDummy, EFFECT_0, SPELL_EFFECT_DUMMY);
+                OnEffectHit += SpellEffectFn(spell_item_vanquished_clutches_SpellScript::HandleDummy, EFFECT_0, SPELL_EFFECT_DUMMY);
             }
         };
 
@@ -1057,7 +1057,7 @@ class spell_item_ashbringer : public SpellScriptLoader
 
             void Register()
             {
-                OnEffect += SpellEffectFn(spell_item_ashbringer_SpellScript::OnDummyEffect, EFFECT_0, SPELL_EFFECT_DUMMY);
+                OnEffectHit += SpellEffectFn(spell_item_ashbringer_SpellScript::OnDummyEffect, EFFECT_0, SPELL_EFFECT_DUMMY);
             }
         };