[gpm] The info and graph widgets

[Richard Hughes <hughsient gmail com>]

Well, the info page is very popular, and the graphs are doing good
things.

If you're not sure what I'm talking about then see:
http://www.hughsie.com/applications/Coppermine/thumbnails.php?album=9

Now all that functionality is currently in the gnome-power-manager
binary, so if the graph stuff crashes, then the whole of g-p-m goes
down. And it pumps up the size of the binary.

What I'm proposing is splitting the graphs from the main g-p-m binary,
but leaving in the "event log" and also the "info page" integral.

This means that "Power Info" would become just the info and event log.

A new executable, gnome-power-graph would be created to show the graphs
and do all the clever statistical stuff.

--

Now splitting the graphs means that g-p-g would need access to g-p-m's
internal data:

* the event dots could be trivially emitted as a signal over DBUS
"lcd-dim" or "suspending" so that g-p-g can just listen for those
signals.

* the graph data could either be emitted as data, or be re-calculated
like we currently do in gpm-power (module sharing, so code duplication
minimal).

*or*

We could just split the data logging program out to be another dbus
mini-service that when we execute the dbus method ShowWindow() shows the
graphs with the data.

*or*

We could leave things as they are.

Comments / suggestions?

Richard.