plugin xep-0054: various improvments on avatars management: - avatars_cache is now managing cache load per profile - use of new profileConnecting method to load persistent data, this prevent to have presence_available trigger called before cache data is loaded - better management of avatars already in cache (prevent decoding avatars when it is already in cache)

[D-BUS Service]
Name=org.goffi.SAT
Exec=sat