This is the protocol that any client should use to talk to cm3s

Requests are sent to cm3s through the status pipe.

Pipes were chosen instead of sockets because even a simple bash script can
write and read on a pipe, therefor allowing people to customize personal 
clients even with bash scripts.

Yes status pipe because the cmd and ststus names are refered to mpg123
and not to the actual interpreter of the commands.
Since the cm3s server part must keep an eye on the status info of mpg123 to
see if it has finished playing a file, while it does that it can also read 
commands sent by client on that same pipe.

The status pipe is located in TMPD/stat (TMPD is defined in the Makefile)
Any response to these commands will come through ipc message.
The ipc message queue key is generated by using tne cm3s executable file
with it's full pathname as defined in makefile ( PREFIX/bin/cm3s )
and a project id that is composed of the character "3".

#E SKIP X
if |X| > 9 then it will skip X tracks
cm3s will respond with how many tracks it actually skipped 
and with the track that is being loaded

@P 0
start plying the next track on the list
cm3s will respond with the track that is being loaded 

#E BEGIN
restart playback from the beginning of the playlist
cm3s will respond with the track that is being loaded

#E RESTART
restart playing current track from the beginning
cm3s will respond with the track that is being loaded

#E PREV
load the previous track that was played
cm3s will respond with the track that is being loaded

#E RAND
toggle random mode
cm3s will respond whether random mode is now on or off

#E REPEAT
toggle repeat mode
cm3s will respond whether repeat mode is now on or off

#L NAME
load the playlist, directory or mp3 file identified by the full path name "NAME"
(or relative to where cm3s was started)
cm3s will respond with the list that is being loaded

#E PAUSE
toggle pause

#E BACKPLAY
Toggle the order the playlist is being played (forward or reverse)

#E SHOWID3TAG

N.B.
In any case cm3s will send an ipc message stating the track that is 
currently being played.
Before doing this cm3s will read and discard any previous messages present
in queue (this prevents the queue from overflowing if there is no client
or if client does not look at the messages).