(svn r2685) -Codechange: Split the music/sound/video drivers into separate files and move them into subfolders.

This results in shorter and hopefully easier to maintain files.
Note: I had to change paths in #include statements of some unrelated files, because I added the ottd base directory to the include path (-I.)

table/engines.h

@@ -5,7 +5,7 @@
   * This file contains all the data for vehicles
   */
 
-#include "../sound.h"
+#include "sound.h"
 
 /** Writes the properties of a vehicle into the EngineInfo struct.
   * @see EngineInfo

table/namegen.h

@@ -1,5 +1,5 @@
-#include "../stdafx.h"
-#include "../openttd.h"
+#include "stdafx.h"
+#include "openttd.h"
 
 static const char *name_original_english_1[] = {
 	"Great ",