[9fans] easier refreshing of acme wins

[Mathieu Lonjaret <mathieu.lonjaret@gmail.com>]

Hi,

I work with many git branches, often affecting the same files. And I
also happen to jump from one to the other quite frequently. There
could be a problem with my workflow, but let's pretend there isn't.

When one of said files is already open in acme, the win won't
automatically refresh it and that's ok, I certainly wouldn't want that
anyway, because I don't always to refresh them all.

However, I find it a bit tedious that I have to write (or paste)
myself the Get tag for each of the wins I want to refresh. To the
point that I'm thinking of hardcoding the Get tag as one of the
"permanent" tags for a win.

Before I do that, does anyone have a better solution to suggest? The
best would be that the Get tag gets automatically added to the tag bar
whenever the files are changed (by git checkout, or other).

p9p acme btw.

Thanks,
Mathieu