Integrate the sponsorship-requests pseudo-package handling

Currently debexpo provides users with a template to create the bug against sponsorship-requests.

In addition to this feature, we could provide further handling by:

Syncing between debexpo comments and sponsorship-requests bug entries (Issue #103)
Displaying RFS status (link to the BTS, some status info like owned/moreinfo)

This will require storing and updating a local state of RFS bugs. We could use UDD or the BTS soap interface (already implemented) to fetch the information from.

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information