Don't raise an error if a field is included more than once.

Log what was found and what was picked.
Log more quietly.
Log more noisily.

Debug is too low-level.
Deduplicate fields.

Do this in getFormFields. Try not to do it repeatedly.
Tidying: don't pass keyword params with default values.
Tweaks.
Fix keyboard fumble.
Don't pass default parameters.
Merge pull request #239 from plomino/jean-first-field-wins

Jean first field wins