Change firefox/thunderbird open dialog application

[David Demelier]

Hello,

When you download a file with firefox or thunderbird you'll get this 
window : http://ompldr.org/vNnJxag

But I would like to switch the application to use for a certain mimetype 
like Text file should use leafpad, http link firefox and so on.

I do not really like to browse to the pointed binary since you cannot be 
sure it will works if you put your configuration on a system where 
binaries are not in the same place and you cannot add additional flags 
neither.

I never found anywhere where you can edit these settings,

Kind regards,

--
David Demelier