Added obsutils.specpoints to make spectral points
Fixed bug when filling spectrum
Add spectrum() function to obsutils and create make_spectrum.py example script to demonstrate its usage.
Merge branch '1290-SpecpointsAndTS' into integration
Add reoptimize_lm() method for TS computation. This avoids an unnecessary recomputation.

Still needs to be seen how the error computation can be switched off for recomputation.
Update ChangeLog and NEWS.