[Seaside] serve jpg image files from form objects

[Bany, Michel]

> asMIMEDocument
> 	| aStream |
> 	aStream _ (RWBinaryOrTextStream on: '').
> 	JPEGReadWriter putForm: (self asFormOfDepth: self depth)
onStream:  aStream.
> 	^MIMEDocument contentType: 'image/jpeg' content: aStream
contents
 
I think you should use JPEGReadWriter2 rather than JPEGReadWriter.