This is a good idea, I was just the other day stuck writing ugly html to
properly size an image for a blog post. Putting the image sizing support
into a plugin instead of trying to shoehorn it into a wikilink seems like
the way to go.

I have two issues with this plugin as it's implemented now, the first is
that the generation of whole pages containing a scaled version of the image
seems gratuituous, as well as buggy. If you want three pages with
differently scaled versions of the image, why not just create three pages
and use the plugin once per page? Something like this on the first one if
it's got multiple clickable thumbnails:

	\[[!img foo.jpg width=256 link=page2]]

This on the second:

	\[[!img foo.jpg width=1024 link=page3]]
	\[[small|page1]]
	\[[medium|page2]]
	\[[large|page3]]

This on the third:
	
	\[[!img foo.jpg link=page3]]
	\[[small|page1]]
	\[[medium|page2]]
	\[[large|parge3]]

Granted, this is more work, but it's more flexible too, and it doesn't have
it creating new pages on the fly, which I don't personally like..

----

The second issue is whether it should use imagemagick to scale the image
and generate a new scaled one, or just emit html that sets the sizes of the
image. Benefits to scaling:

1. Saves download time and bandwidth, especially if generating a page with a
   lot of thumbnails of large images.

Benefits of not scaling:

1. Avoids any security issues with imagemagick.
2. Avoids issue of how to clean up old scaled images that are no longer being
   used. (Granted, this is a general ikiwiki problem that will eventually
   be fixed in a general way. (Update: now fixed in a general way, use the
   will_render function.))
3. Makes clicking on thumbnails display the full version really fast, since
   it's cached. :-)

--[[Joey]]
