Core/Scripts: Split script subdirectories into independent modules

* Makes it possible to define the linkage for every module
* Move the ScriptPCH into the root directory
* Changes the SCRIPTS cmake variable to a string type:
  -> -DSCRIPTS=0 is -DSCRIPTS="minimal-static" now
     (builds commands and spells statically)
  -> -DSCRIPTS=1 is -DSCRIPTS="static" now
     (builds all modules statically)
  -> -DSCRIPTS="dynamic"
     (builds all modules dynamically)
  -> Also the default value which is provided by the SCRIPTS
     variable is overwriteable through the SCRIPTS_COMMANDS,
     SCRIPTS_SPELLS... variable.

src/server/scripts/ScriptLoader.cpp.in.cmake

@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2008-2016 TrinityCore <http://www.trinitycore.org/>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+// This file was created automatically from your script configuration!
+// Use CMake to reconfigure this file, never change it on your own!
+
+#cmakedefine TRINITY_IS_DYNAMIC_SCRIPTLOADER
+
+#include "Define.h"
+#include <vector>
+#include <string>
+
+@TRINITY_SCRIPTS_FORWARD_DECL@
+#ifdef TRINITY_IS_DYNAMIC_SCRIPTLOADER
+#  include "revision_data.h"
+#  define TC_SCRIPT_API TC_API_EXPORT
+extern "C" {
+
+/// Exposed in script modules to return the script module revision hash.
+TC_SCRIPT_API char const* GetScriptModuleRevisionHash()
+{
+    return _HASH;
+}
+
+/// Exposed in script module to return the name of the script module
+/// contained in this shared library.
+TC_SCRIPT_API char const* GetScriptModule()
+{
+    return "@TRINITY_CURRENT_SCRIPT_PROJECT@";
+}
+
+#else
+#  include "ScriptLoader.h"
+#  define TC_SCRIPT_API
+#endif
+
+/// Exposed in script modules to register all scripts to the ScriptMgr.
+TC_SCRIPT_API void AddScripts()
+{
+@TRINITY_SCRIPTS_INVOKE@}
+
+/// Exposed in script modules to get the build directive of the module.
+TC_SCRIPT_API char const* GetBuildDirective()
+{
+    return _BUILD_DIRECTIVE;
+}
+
+#ifdef TRINITY_IS_DYNAMIC_SCRIPTLOADER
+} // extern "C"
+#endif