Calls the System V IPC function msgsnd to send the message MSG to the
message queue ID. MSG must begin with the native long integer message
type, and be followed by the length of the actual message, and finally
the message itself. This kind of packing can be achieved with
pack("l! a*", $type, $message)
. Returns true if successful,
or false if there is an error. See also IPC::SysV
and IPC::SysV::Msg
documentation.