Update to V1.0.3.7

Version 1.0.3.7 is another maintenance update that fixes some possible minor bugs and updates the default mapsources.

Important notice: This update overwrites the mapsources.xml with the default one. If you are using a custom mapsource.xml, you need to sync it from NaviMapper again after the update. Please note that the 4umaps server has changed, providing us with more power and speed in the future. So if you use a custom mapsources.xml, you will have to change the tile URL because the old 4umaps tile server will stop its service soon. The new 4uMaps server is http://tileserver.4umaps.eu/%z/%x/%y.png . The NaviMapper PC application will be updated accordingly very soon.