No way of marking duplicate specifications

[Matthew Paul Thomas]

As the number of specifications registered for Ubuntu approaches 1000, predictably, duplicates are emerging. For example:
* https://launchpad.net/distros/ubuntu/+spec/xorg-server is a duplicate of https://launchpad.net/distros/ubuntu/+spec/xorg-config-ui
* https://launchpad.net/distros/ubuntu/+spec/userfriendly-filesystem-structure is a duplicate of https://launchpad.net/distros/ubuntu/+spec/stop-filesystem-apartheid
* https://launchpad.net/distros/ubuntu/+spec/eye-candy is effectively a duplicate of https://launchpad.net/distros/ubuntu/+spec/composite-by-default
* https://launchpad.net/distros/ubuntu/+spec/selinux-by-default is a duplicate of https://launchpad.net/distros/ubuntu/+spec/selinux

Launchpad has no way of marking these duplicates, which means contributors are likely to work on one without noticing the progress being made on the other. And as the number of specifications increases, drivers are less and less likely to notice the duplicates themselves.

Therefore it should be possible for anyone to mark one specification as a duplicate of another, just as they can currently for bug reports.