Update integrate.js

First function version of Jango service integration for Nuvola 3
Update metadata.json

First function version of Jango service integration for Nuvola 3
Update README.md

Added copyright informations
Fixes suggested by fenryxo
Merge functional Jango script

Service integration script ported from Nuvola Player 2.

Reviewed by: Jiří Janoušek <janousek.jiri@gmail.com>
Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>