[GRASS5] [5.7] adding maps with d.m from diff't mapsets

Hi,

right now it isn't obvious how to add maps from different mapsets in
d.m [you have to run g.mapsets first and tick any you want to be added
to the tree]. Perhaps it is better to list all mapsets; any ticked in
g.mapsets are expanded, all others collapsed (if that is even possible)?

It isn't a bug, but it looks to the user like one and it isn't intuitive
how you add them. Maybe it is better if we can add a mapsets button that
calls g.mapsets on the select map (tree) window?

Hamish