Make mouselook use internal extended command

... instead of faking a key press

include/func_tab.h

@@ -13,6 +13,7 @@
 #define GENERALCMD   0x08 /* general command, does not take game time */
 #define CMD_NOT_AVAILABLE 0x10 /* recognized but non-functional (!SHELL,&c) */
 #define NOFUZZERCMD  0x20 /* fuzzer cannot execute this command */
+#define INTERNALCMD  0x40 /* only for internal use, not for user */
 
 struct ext_func_tab {
     uchar key;