Add retrieved iono parameters to log file

[Ian Culverwell]

ROPP8.0 beta reviewer Sean Healy (ECMWF) suggests:

Looked at the t_1dvar_iono_bangle.log file. The defaults H_peak=150 
km, H_width=25 km seem a bit low/thin respectively. It might be 
useful to have the retrieved values in this log file. 

I chose the default ne_max, h_peak and h_width etc on the basis of tests on some standard test datasets. These vals gave the best overall behaviour (best fit at top in fewest iterations), so I don't want to change them without evidence. The retrieved vals are in the output file, but I agree we should add them to the log file. I also think it needs stressing that the background values are changed by the 'preprocessing' fit to L1-L2, and perhaps there ought to be a switch to turn that off. But users will have difficulty converging to anything useful without it.

[Ian Culverwell]

Defer to ROPP10.0.

[Ian Culverwell]

Defer to ROPP-11.0.

[Ian Culverwell]

No-one's interested in L1 + L2 retrievals any more, so cancelling this ticket.