GPS positioning

I made good progress during the last days.
Map drawing is working except for dashed ways.
Positioning the map to the GPS position is also working again. This involves an architectural change - the interested objects register directly with the LocationProvider. The latter puts the data into the data objects (PosData mainly).
I also fixed some errors such as a crash when a POI icon could not be found in the map ZIP.
So I think a first binary release with native Android GUI - which will be more of an alpha release though - is not far away.