Implemented suggestion "Script Command to block commands" http://rathena.org/board/topic/88888-script-command-to-block-commands/

-- Added new script commands: 'enable_command', 'disable_command'
-- Added new config 'atcommand_enable_npc' at conf/battle/gm.conf
-- Thank Kichi for the patch file

Signed-off-by: Cydh Ramdh <house.bad@gmail.com>

src/map/script.h

@@ -134,6 +134,7 @@ struct script_state {
 	unsigned npc_item_flag : 1;
 	unsigned mes_active : 1;  // Store if invoking character has a NPC dialog box open.
 	unsigned char* funcname; // Stores the current running function name
+	uint8 atcommand_enable_npc;
 };
 
 struct script_reg {