use mime types for image and other format names
Currently, morpho understands "gif", "jpeg", jpg", and some other arbitrary
format names. At a minimum, we need to also allow mime type designations (e.g.,
"image/gif"). As part of this, it would be nice if the data import wizard
detected that the file being imported is an image so that it can skip
meainingless screens of information such as "attribute" lists (which are
#1 Updated by Dan Higgins almost 20 years ago
Most users are unlikely to know what a 'mime-type' is. 'format' in the physical
module in the wizard should thus be a choice element with choices meaningful to
the user (and which insert mime types in the eml)
Also, I don't know of an easy way to detect image files (other than extenders).
Need to find out if the first few bytes indicate file type.