Improve error handling

[dchud]

Currently, when an error arises with a particular subject in the adult algorithm, an error message is printed and processing stops, e.g.: Error in !binerr_interpol : invalid argument type. This gives a hint about the step, but not which subject. It also halts execution. We can make a few improvements on this:

• Capture the subject, error, and ideally step where it happens
• Continue processing despite the error to complete the file if possible
• Report on errors after (or during?) processing, to console by default, but maybe to file optionally?

[dchud]

Removing from 2.0, for later work.