Switch to plus7 REST API

[jeanparpaillon]

Using the plus7 REST API is more reliable and faster.
Downloaded JSON file is cached for 30 minutes (default).
plus7 code grabbed from

[AddonScriptorDE]

Hi,
thanks for your work :)
I was already thinking of using the REST Api, but it has to much disadvantages:

• lower video quality
• no thumbnails
• only +7 (no vids of the day, bonus, events, search, concerts)
• no categories
• no sorting

Also, arte.tv got much faster last months. So, speed is not longer a problem.