Add "sticky" comments to AddOns

[Baertram]

Hey Dolby,

please allow us to add at least one sticky comment to the addon comments.
This would make life so much easier for us and the users as we can post FAQ links, and most up2date info about bugs etc. in there and they would not scroll down each time.

The users do not check the chagelog or description. They ONLY read comments, if they do this at least.

Many many many many many thanks for making this happen!
Baertram, speaking for the devs