Thread manager

Hi,

While working on Vladimir's patch, it reminded me of an idea I wanted to
share.

Right now, when you launch a dump, or a VACUUM, the UI kinda sucks
because it puts you on another tab, still in the same dialog, and you
can't be sure you can do something else while the work is ongoing. It'll
worse with Vladimir's patch as there is no UI at all to show the
progress on the copy (if you copy more than one table of course).

I was a few weeks ago at a customer's office, and he showed me a nice UI
of a tool (unfortunately, I don't remember its name) that allowed him to
queue some jobs. So I wondered if we could do the same. When you're in
the VACUUM dialog, and click OK, it adds a job in the jobs list, and a
thread will catch it as soon as it is available for a new job. The UI
could be as simple as a new pane in frmMain, with a listbox which
contains the list of job, and their status. We could use if for the
"copy table" patch. We could also use it for the dump/restore dialog.
And there are probably more things to do with it. We could probably add
buttons to pause/resume waiting jobs, and to drop jobs.

IIRC, a long time ago, Peter sent a patch to show the progress of a job
(VACUUM I think, but I might be wrong). Unfortunately, it has been
rejected, but I guess someone (maybe Peter himself) will want to work
again on this. And this would be the perfect UI to show that kind of
information. Yeah, I know, that part is more a dream than a reality, but
it's a nice dream :)

Anyways, comments?

--
Guillaume
http://blog.guillaume.lelarge.info
http://www.dalibo.com