convert geo to Format class. (#998)

convert geo to Format class. (#998)

This also adds the encoding attribute to the xml declaration.
This also starts the loc element at the beginning of a line.
Previously we jumped through some hoops to avoid the above two
changes so we could exaclty match the original reference file.

We also pass the writer to the waypt_disp_all callback via a lambda.
This allows the output File and QXmlStreamWriter to be local which
simplified cleanup.