guix.el: Key bindings for a "package list"

[Alex Kost]

Hello,

I would like to know people's opinions about default key bindings.

Currently in a buffer with a list of packages we have: "u"/"U" to
unmark/unmark all.  But it leaves no room for marking for upgrade and I
just bound it to "^" which is not very good.

So what about combining "unmark"/"unmark all" into one key and use
either:

1. "U" - unmark ("C-u U" - unmark all);
   "u" - mark for upgrading.

2. "u" - unmark ("C-u u" - unmark all);
   "U" - mark for upgrade.  Should it also require (for consistency) to
   use upper-case "I"/"D" for marking for installing/deletion?

Also should there be a command to mark all obsolete packages for
upgrading?  If so, what key should it be bound to? (perhaps my favourite
"^").

Thanks.

--
Alex