relax SVN archive

Created a new branch for the implementation of inversion-recovery R1 curve fitting.

This is the first step for the corresponding task:
https://gna.org/task/index.php?7415

This follows a thread started at:
https://mail.gna.org/public/relax-devel/2011-06/msg00138.html
Message-id: <4DF8A720.9000006@...>