feed items lack *unique* GUID

[Darwin Survivor]

The feed for an idea uses "items" to list comments to that idea. The GUID for each item, which is *supposed* to be unique, is in fact the url to the *idea*. This means every item in that feed has *identical* GUID's, making it virtually impossible for many feed readers (such as newsbeuter) to properly distinguish one comment from another.

The GUID's need to be unique, I suggest using the database id of the comment as the GUID, or possibly combining it with the idea's id and/or the date & time of the comment.