All PSM issues now have labels matching them to RTM requirements.

[Karl Fogel]

Each issue in the PSM issue tracker -- both open and closed tickets --
now has labels linking that issue to all the RTM requirements it's
related to. Some new requirements were created in the process; look
at recent commits to requirements/RTM.xlsx for details.

The labels all have a black background, and all begin with
"Z-REQ-PSM-". The "Z-" prefix is to make them always sort at the end
of the list in the labels dropdown, so that they don't get in your way
when you're trying to pick a normal label interactively. Comments
welcome. It wouldn't be hard to change the background color, or some
other aspect of these labels, if someone really wants it.

Our plan is to keep this information up-to-date as we file new issues,
and to use the issue<->requirement linkage programmatically as an
ingredient in generating a project status dashboard (the mechanics of
which are still TBD).

I'll attach a transcript here of the batch script session that set all
these labels, in case anyone is curious.

Best regards,
-Karl