Shifted the peak list selection GUI component used in the R1 and R2 into its own class.
This was discussed at https://mail.gna.org/public/relax-devel/2010-01/msg00093.html (Message-id: <7f080ed11001290600h42a4dd0lfc05bbf5889816e4@...>).
Authored by: bugman 2010-01-29
Parent: [r10597]
Child: [r10599]