script to export images

[Carl Karsten <carl personnelware com>]

I have a diagram with 7 layers.  I need to export 6 png images with
the following layers visible:

base [5]
crowdcam [3,5]
sound_cam [1,3,4,5]
sound_alsa [1,2,3,5]
monitor [1,2,3,5,6]
streaming [1,2,3,5,6,7]

If I make a change, I need to export again.  If I make a change to
layer 5, I need to export all 6.  If I need to export to a different
format (svg), all 6 again.  This is getting annoying.  How can I write
some python that will do this?  It is specific to this .dia, so I
wouldn't want it made part of the .dia system, although if keeping it
external is any sort of hassle, I don't really care if it lives in my
Dia.

-- 
Carl K