+upstreamtask and +packagetask need to become context-aware

Currently, +upstreamtask and +packagetask (which are gotten to when clicking either "File Against Upstream..." or "File Against Package..." when looking at a /malone/bugs/$bug.id page) bring the user to a non-context-aware page.

A context-aware bug filing page is a bug filing page where the upstream or distro/sourcepackagename/binarypackagename are already known and thus there is no entry field on the form to collect such data.

+upstreamtask should bring the user to a page where they search for an upstream, click on it and *then* file a bug on a context-aware bug form.

+packagetask should bring the user to a page where they search for a distro and (optionally) a sourcepackagename and (optionally) a binarypackagename. Once they've found the most specific thing they're able to report on (a distro, a distro sourcepackagename, or a distro binarypackagename), they should be able to click on that and again be brought to a context-aware form to file the bug.

Solving this problem may also involve changing the URL-space, but I'll leave that to be figured out by whoever writes the proposal on this. :)