In Toaster it is desirable to be able to split the list of files by the IMAGE_FSTYPES item that produced them. At the moment we can do this just by treating the item (e.g. ext3, tar.bz2) as the file extension, except for "live" which produces iso and hddimg files.

One way to handle this would be to have the metadata declare a list of globs matching the files that the type is expected to produce, e.g. 

  IMAGE_TYPE_FILES_live = "*.iso *.hddimg"

Toaster could then read these and use them for splitting the files.