Added test data where both the spin-lock time, the spin lock offset and the spin lock field is varied.

The data is published in:
A Folded Excited State of Ligand-Free Nuclear Coactivator Binding Domain (NCBD) Underlies Plasticity in Ligand Recognition.
Kjaergaard, M., Andersen, L., Nielsen, L.D. & Teilum, K. (2013).
Biochemistry 52, 1686–1693

with experimental conditions that
"off-resonance R1rho relaxation dispersion experiments on 15N were recorded at 18.8 T and 31 C."
"using the pulse sequence of Mulder et al. with spin-lock field strengths from 431 to 1649 Hz and offsets ranging from 0 to 10000 Hz."
Shifted the 'NS CPMG 2-site expanded' model to the top of the CPMG numerical solutions in the manual.

This is because this is the default model which should be used in most cases.