It should be easier for a user to set a application as default mime opener

[lupus <de_lupus pandora be>]

This patch extends the "Open with..." dialog. So that you can set it as
default mime handler.


Since a picture says more then a thousand words:
http://bugzilla.gnome.org/attachment.cgi?id=85713

patch at:
http://bugzilla.gnome.org/show_bug.cgi?id=422100

Kristof Vansant