Bugs not under /ubuntu not shown in bugs to sponsor

[Timo Jyrinki]

A more global search https://bugs.launchpad.net/bugs/+bugs?field.subscriber=ubuntu-sponsors finds a few bugs that should not be hidden from view.

Examples of such:
https://bugs.launchpad.net/lucid-backports/+bug/853511 - bugs against 'Backports' projects
https://bugs.launchpad.net/ddtp-ubuntu/+bug/1184952 + https://bugs.launchpad.net/ddtp-ubuntu/+bug/1184952 (need DDTP updates to repos)
https://bugs.launchpad.net/grub-customizer/+bug/841191 - bugs against upstream projects that would like to be included in Ubuntu

There's a small handful of such bug reports, but not eg too many in addition to above at the moment. I targeted a couple against Ubuntu but that not should be absolutely required if the subscription is there.

I added a note about this global search URL to https://wiki.ubuntu.com/SponsorshipProcess.