depend on jansson 2.4 instead of 2.5
Add camera array
Add audio array, but with audio api changes.

In the old php api for audio, all infos were queried in the get_home
command. This approch gaves long time for the first get_home query. To
be more efficent now, we only returns basic informations and some more
api command for audio need to be added that let the client query for
audio stuff (vollume, status, time, playlist, etc...)
Add poll_listen api command