Some NMEA file parsing problems

[routeconverter]

My primary wish was to convert between formats without losing any digits of original data.

Actually that's a goal for RouteConverter, too. But I decided to stay within the limits of the file formats.

The primary problem of rounding errors can be easily demonstrated, if you open the GPX file, save it as NMEA; open the resulting NMEA and save it back to GPX and do the diff.

With the increased internal precision this might go away

No, the problem is that NMEA and GPX positions need to be converted and that NMEA limits the number of digits.

but I think you'll still need more digits in the GPX and NMEA file for the above process to retain all of the original digits without rounding errors. That's why I introduced additional registry entries for more digits.

Agreed, you need the additional digits. Please try to do a pull request against the latest commits.