Fetch some ABP AMO data periodically and save it to the file

[saroyanm]

Background

As mentioned in #1880 we would like to show rating on Firefox landing page, but for that we need periodically download ​AMO data and save to our server.

What to change

Run script every week that will fetch ​AMO data and save "rating" and "reviews" tags into the XML file on our server that runs anwiki, the file should be accessible from anwiki abp_output plugin.

[sebastian]

I guess, since we don't use Anwiki anymore, it probably makes more sense (if this feature is still desired) to implement it similar to how we ​fetch and show supported browser versions now, rather than having a separate cron job fetch those data.

[saroyanm]

I think this issue was created a long time ago and while we are planing in future change the hompage and probably re-implement it I think it's better to close the issue for now, I think it doesn't worth the effort.
Also using fetching browser version is throwing exception from time to time:
https://issues.adblockplus.org/ticket/3986
https://issues.adblockplus.org/ticket/3773

I'm not sure if it make sense to rely on existing script that fetch the data and introduce additional potential exceptions.

[trev]

Fetching browser versions queries update servers which aren't meant to produce visible errors - if something fails the browsers will simply retry. AMO's API on the other hand is fairly reliable, we used to query it and there were only occasional errors, never something that persisted over days.

Whether doing this is worth the effort is another thing of course, with our CMS it would be fairly simple. We definitely don't need anything in sitescripts however, so this issue can be resolved - #1882 will suffice.