Proper uninstallation of SPKGs

[Erik Bray]

Hi all,

I'd like to call attention to a new ticket I've added, #25139 [1]
which proposes to add a new mechanism for *cleanly* uninstalling
already installed SPKGs (particularly optional/experimental packages,
though it can be used for standard packages as well--not that you
generally should).

This is a followup to an earlier ticket #22510 [2] which was
essentially the same work, but did a little bit too much at once, so
I've broken into a couple smaller tickets, and rebased it on the
current develop branch.

I'm calling attention to this work here in particular since I know
several people here in the past have expressed desire for supporting
proper package uninstallation--well this is it. It has a few other
smaller tickets as dependencies that need review as well.

Thanks,
E



[1] https://trac.sagemath.org/ticket/25139
[2] https://trac.sagemath.org/ticket/22510