Xe Ln Versions Save

This library is no longer being actively worked on. Users should switch to log/slog instead.

• Fix context storage
• Support golang.org/x/exp/errors

• status reporting for ex.HTTPLog
• testing improvements
• allow errors to be Fers

• LN_FORMATTER=json to implicitly output json instead of logfmt key->value pairs
• AddFilter function to add things to the filter list in the best way