CollageGFX

What does collage need to do:

Align multiple (unspecified number of) images on a single page.
Images need to be interactively scalable.
Images need to be given a stacking order and a blending type.

To do this it needs:

1. Interactive wireframe preview window
	a. each image is a frame in display
	b. each frame must be selectable by a mouse click
	c. each frame must be independently mobile
	d. each frame must be drawn given its current orientation (rotation).
	e. each frame needs extra line drawn across top of outline to show where
		the top is for that image.
	f. each frame must be identifiable from within the preview
		1. use gdk_font_load() - see text_tool.c for how to use this - and
			draw ids in the frames
	g. currently selected frame has:
		1. colored outline
		2. resize grab boxes.

2. Image options
	a. selection
	b. scaling
	c. layer options
	d. stack position
	e. rotation options - this requires embedding TransGFX?

3. Page options
	a. page size - interactive/manual settings
	b. margins
	c. DPI
	d. current page size in Kb.

3. Real preview 
	a. generate new image at very reduced size
	b. for each selected image
		1. create copy of image at reduced preview size
		2. copy original into copy
		3. add blended layer and position it
	c. flatten
	d. copy to preview window
	managing this may be hard - I probably don't want to get rid of the
	preview image copy (the one with layers) since that would speed up
	previews.  But maybe for the first version thats what I'll do.

It looks like some of these things (page size, margins, dpi for example)
may be candidates to be moved into common-d.  They seem to be items
necessary on many of these plug-ins.
