Allow user to change tiles used in map view

[jsavage]

Hi all,
Just as OSM tracker can now display recorded tracks on OSM, it would also be useful to be able to do the same using https://map.openseamap.org/
possibly also others
http://www.opencyclemap.org/ ??

My suggestion would be to do this in the most generic way but have the ability for users to select which one they want in settings.
Perhaps:
New Setting: Default OSM Source (similar to "Camera" versus "Gallery" versus "ask me each time"). ie with the ability to select from available OSM variants and "ask me each time".

If i understood the implications I would be happy to help implement this.

James