Core/Game: Add a dynamic script reloader which reloads scripts modules on changes.

* is responsible for registering plain modules.
* requires compilation with the `WITH_DYNAMIC_LINKING` flag.
* requires further support of the ScriptMgr.

src/server/game/Scripting/ScriptMgr.h

@@ -833,8 +833,6 @@ class TC_GAME_API GroupScript : public ScriptObject
         virtual void OnDisband(Group* /*group*/) { }
 };
 
-// Placed here due to ScriptRegistry::AddScript dependency.
-#define sScriptMgr ScriptMgr::instance()
 
 // namespace
 // {
@@ -851,12 +849,13 @@ class TC_GAME_API ScriptMgr
         ScriptMgr();
         virtual ~ScriptMgr();
 
+        void FillSpellSummary();
+        void LoadDatabase();
+
     public: /* Initialization */
         static ScriptMgr* instance();
 
         void Initialize();
-        void LoadDatabase();
-        void FillSpellSummary();
 
         const char* ScriptsVersion() const { return "Integrated Trinity Scripts"; }
 
@@ -872,6 +871,12 @@ class TC_GAME_API ScriptMgr
             _script_loader_callback = script_loader_callback;
         }
 
+    public: /* Script contexts */
+        void BeginScriptContext(std::string const& context);
+        void FinishScriptContext();
+
+        void ReleaseScriptContext(std::string const& context);
+
     public: /* Unloading */
 
         void Unload();
@@ -1094,10 +1099,13 @@ class TC_GAME_API ScriptMgr
         void ModifySpellDamageTaken(Unit* target, Unit* attacker, int32& damage);
 
     private:
-
         uint32 _scriptCount;
 
         ScriptLoaderCallbackType _script_loader_callback;
+
+        std::string _currentContext;
 };
 
+#define sScriptMgr ScriptMgr::instance()
+
 #endif