Don't allow modifying qvms or pk3s

Exception for allowing pk3s to be downloaded.

code/qcommon/qcommon.h

@@ -641,7 +641,7 @@ fileHandle_t	FS_FCreateOpenPipeFile( const char *filename );
 
 fileHandle_t FS_SV_FOpenFileWrite( const char *filename );
 long		FS_SV_FOpenFileRead( const char *filename, fileHandle_t *fp );
-void	FS_SV_Rename( const char *from, const char *to );
+void	FS_SV_Rename( const char *from, const char *to, qboolean safe );
 long		FS_FOpenFileRead( const char *qpath, fileHandle_t *file, qboolean uniqueFILE );
 // if uniqueFILE is true, then a new FILE will be fopened even if the file
 // is found in an already open pak file.  If uniqueFILE is false, you must call