[fix] use defined constant for hlep msg
rename PlayerControl.is_playing to PlayerControl.status (future work)

status returns playing/!playing, someday it will also return metadata info
separate status from is_playing in PlayerControl

PlayerControl.is_playing is required internally, status() is only used to answer to clients
[fix] left over def from before shared.py
[fix] logging error
[add] play queue -> add+play

WIP:
    5: 'quede_del',
    6: 'quede_get',
    7: 'queue_clear',
    8: 'queue_next',
    9: 'queue_prev',
[add] queue_add from local directory
[fix] typo
[add] queue_del func
[add] current uri. status returns the info
[add] clear queue
[add] queue_get
[fix] avoid repeating last item forever
[fix] hnadling of del of (first,current) element of queue
[add] state always returns currently loaded url (playing or stopped)

when stopped, this is useful to determine what will be played upon the next call to 'play'
[clc] debug leftovers
[add] server<->client comm using json
[add] duplicate entry log but allowed (may want to repeat in queue)