FCM

Purpose:        File Change Mode (CHMOD)

Input Syntax:   FCM <who> <how> <what> <filename>

Input Params:   <who>      INT =       0x01 : owner
                                       0x02 : group
                                       0x04 : others
                <how>      CHAR(1) =   + : add
                                       - : remove
                                       = : set 
                <what>     INT32 =     mode
                <filename> CHAR(256) = file name

Output Syntax:  +|-

Output Params:  none

Right required: none

Implementation: serverd.c / file_chmod()

Remarks:        permission check is done by ftps
