An unfortunate number of contributors are manually attaching patches
instead of using "darcs send". This results in .dpatch attachments of
type application/octet-stream instead of text/x-darcs-patch.
Suggest extending roundup or the patchs@darcs.net script to recognize
attachments named *.dpatch with type application/octet-stream and
munge the MIME type to text/x-darcs-patch.