Add-on Update Notifier 1.1.8

Don't show version/download/changelog info in the "Upgradeable" box.
(When FTP uploading zip archive with new version)

Since @Xon has started using a special versioning format to streamline their development, we needed to update our backend to be able to map their released version_string values to the actual version_id values used.

This is a backend change so there is no need for updating the add-on on your site, and you should start getting update notifications for Xon's add-ons correctly again.

Since it was requested by a few customers to allow more add-ons, we decided to add 2 new tiers..

If you currently have e.g. 60 extra add-ons and choose to upgrade to 120 extra, the remaining days on your current license will be prorated, e.g. 50 days remaining on license @ 60 extra add-ons becomes 25 days remainings @ 120 add-ons + 1 year from that date.

The previous version didn't check that the response was JSON and tried to decode it as such, which would raise an error in case the API request returned some funky data due to timeout or similar.

Some phrases had been added during development when we tested the 90-prefix in versioning.

This release resets them to be on version 1010391 rather than previous wrong value of 901000070

Some forum owners seem to have missed the detail about setting up an API key for the add-on to work, so we now also show a message at the top of the add-on page so they notice it at some point

• Show info if your forum is blocking the callback about new updates
  • This message can be disabled in the add-on options

Fixed 2 phrases that were incorrectly marked as version 10.0.5 from a bad version bump earlier.

• AUN is not counted when showing the used amount add-ons from the limit
  • The backend already had this, but frontend didn't correctly indicate it.
• Exclude legacy add-ons, thanks @SeToY
  • Not checked
  • Not counting toward limit
  • Not showing any indicators
• Added a missing ? to phrase, thanks @Nicolas FR

This fix hides the "waiting to be checked"-clock indicator for add-ons that will never be checked