Python Use UTF8 and untranslated Series Names

.. With german translation activated GC.activity() complains about
   some utf-8 decoding stuff and returns error.

   First I thought came from the real activity json file, but it's
   from translation: Altitude -> Höhenmeter.

   Is it necessary to use toLatin1() in goldencheetah.sip? With
   toUtf8() it works and you get delta symbols instead of question marks.

.. With R the series names are always in english and use a naming
   convention derived from the R trackR package -- we now follow the
   same in Python bindings to ensure charts created in one locale
   will continue to work in another.

src/Python/SIP/Bindings.cpp

@@ -54,7 +54,7 @@ Bindings::seriesLast() const
 QString
 Bindings::seriesName(int type) const
 {
-    return RideFile::seriesName(static_cast<RideFile::SeriesType>(type));
+    return RideFile::seriesName(static_cast<RideFile::SeriesType>(type), true);
 }
 
 bool