arima, exact ML: --opg (and set arma_vcv op) does not give the outer-product-of-gradient covariance, and --robust inherits it.
Snapshots are now on the way. I'll close this ticket shortly, but if problems with the new code emerge, it can be reopened.
hpfilt(): default λ for annual and monthly data, Ravn and Uhlig's 6.25·pd⁴ rather than 100·pd² (follow-up to gretl-devel, October 2016).
We decided to switch to the formula for lambda recommended by Ravn-Uhlig (2002). This is now done and documented.
complete the hpfilt lambda update
update an error message
bufgets: guard against zero-size target and tidy the scan loop
gretl_edit: fix bogus E_TOOLONG when (re-)loading functions