Core: Move FormationMgr to namespace

Also...
- Warning fixes
- Make Singleton constructors private

src/server/scripts/Northrend/Ulduar/ulduar/boss_flame_leviathan.cpp

@@ -1666,7 +1666,7 @@ class spell_pursue : public SpellScriptLoader
                         caster->AI()->EnterEvadeMode();
             }
 
-            void HandleScript(SpellEffIndex eff)
+            void HandleScript(SpellEffIndex /*eff*/)
             {
                 Creature* caster = GetCaster()->ToCreature();
                 if (!caster)

src/server/scripts/Northrend/Ulduar/ulduar/instance_ulduar.cpp

@@ -509,7 +509,7 @@ class instance_ulduar : public InstanceMapScript
                 }
             }
 
-            void SetData64(uint32 type, uint64 data)
+            void SetData64(uint32 /*type*/, uint64 /*data*/)
             {
             }