There are now three places where Squeak is presented with binary data
and a guess at a content type: Scamper, FileList, and now Celeste.  We
also have three independent ways to deal with this:
MailMessage>>bodyFormattedText, FileList>>fileListMenu, and
Scamper>>displayDocument:.

This situation is crying out for unified handling.  I don't have a
specific proposal, but the following seem like good things to keep in
mind:

	1. There should be a way to add new content-type handlers on a
package-by-package basis.
	
	2. Let us absolutely *not* use this stuff internally--classes are much
better than content-types.

	3. The user should get a choice about how the document is treated, but
we should make it easier to do the most obvious thing.  For example, if
it's image/foo, then make it easy to view the data as an image.

	4. One possible definition of "view", is "generate a Text instance,
possibly with embedded morphs".  Another is "just give me a morph!".



-Lex