gpx writer may violate schema

[tsteven4]

gpsbabel -i gpx -f reference/track/gpx_subsecond-sample.gpx -o gpx -F x.gpx

produces trkpts like:

      <trkpt lat="49.794688000" lon="9.834015000">
        <ele>289.200</ele>
        <time>2011-07-02T17:47:25.200Z</time>
        <speed>13.818100</speed>
        <name>trkpt-2011-07-02T17:47:25.000Z</name>
        <fix>3d</fix>
        <type>T</type>
      </trkpt>

The gpx 1.0 schema requires the fix element to be after the type element:

              <xsd:sequence>  <!-- elements must appear in this order -->
...
              <xsd:element name="urlname"   type="xsd:string"   minOccurs="0"/>
              <xsd:element name="sym"     type="xsd:string"   minOccurs="0"/>
              <xsd:element name="type"      type="xsd:string"   minOccurs="0"/>

              <!-- Accuracy info -->
              <xsd:element name="fix"     type="gpx:fixType"    minOccurs="0"/>
              <xsd:element name="sat"     type="xsd:nonNegativeInteger" minOccurs="0"/>

The type element is printed by fprint_xml_chain. This also violates the gpx 1.1 schema when using "-o gpx,gpxver=1.1"

[tsteven4]

fixed in #1191