flyspray: add removed packages script

This script goes through all open bugs in the Arch Linux and Community tracker and extracts the packagename from "[$pkgname]" and tries match it to the list of packages in the repo. If there is no match the package is assumed to be dropped from the repo and printed.

This script will give false positives, but not enough which requires some extra filtering.

Main reason to check it in, is to:

1. help with migration to drop old issues
2. not have it around on my desktop :-)
3. sharing is caring