[Evolution] never ever show this thing again

[Bill Kenworthy <billk iinet net au>]

Crap, just did new build of evo and the that anoying (i.e., as bad as
the paperclip) "this is experimental software ..." dialog is back.  If
you insist on including it, can we at least get a button that says
"never ever show this thing again" on it? - I *KNOW* this is the dev
version, thats why I installed it, I dont need a dialog to tell me that
*EVERY* time I start it up!

BillK