Add errstate ignore to the gw.conversion module

Further minor changes pulled out of !905 (merged)

• Add errstate ignore wrappers to a few other places. The rational for this is we understand why they error (the MCMC sampler proposes non-physical parameters). Without these ignore statements the .err files quickly get full of such warning messages.

changed milestone to %1.1.2

approved this merge request

approved this merge request

merged

mentioned in commit 0437e0b1