Version 0.90.7

Returning credits now checks whose credits they are.

When an upload is charged and then fails, the charge is reversed automatically. That reversal found the entries to undo by the upload’s reference string alone, and never checked that the account asking owned them. The reasoning was that no stranger’s reference string could reach it — true for credit-paid uploads, but not for the other place references are made, where the string is built from a file id anyone you have shared with holds. Nothing could be reversed this way today because the fee on that path is zero; the defect was that the only thing stopping it lived in a comment rather than in the query, and it is now in the query.