Improve serials

[cathoderaydude]

Serials suck atm.

1. Add a DownloadUUID column (nillable) to tie a serial to a given download (windows 98 oem vs retail -_-)
2. Display any linked serials on the download info page
3. Add an ID PK to the Serials table and backfill :(
4. For anyone who's an admin, expose an AJAX insertion prompt in the serials field so we can quickly comb the comment threads

[NattyNarwhal]

for 1, that does mean we'd have to link it for foreign language copies too. 2. can be done through just 2. too, 3. is a simple script once the column is added (plus adding the trigger), 4. i assume you mean just have a field on the non-editing products page for it?

[cathoderaydude]

Yeah I guess we could just have a form that submits to the add serial route, no ajax bs needed?