Comment 12 for bug 2132

On further investigation, we can't do this, because:
* top-level URLs now belong to projects (e.g. launchpad.net/ubuntu, launchpad.net/firefox)
* projects can have IDs consisting entirely of numerals (e.g. bugs.launchpad.net/1234 shows the bugs filed against the "1234" project)
* even if we tried to disambiguate them by introducing a rule that project IDs must have at least one non-numeric character, we'd still have the problem that bugs can also have non-numeric nicknames, and it would be unreasonable for those nicknames to work in some places and not others.