Switch to OAuth 2 for OpenStreetMap provider

[danieldegroot2]

Switch to OAuth 2 from HTTP Basic Auth and OAuth 1.0a. They are being deprecated.
See openstreetmap/operations#867

[mmd-osm]

Current OSM OAuth 1.0a based login doesn't work since a while, see #93

[harry-wood]

Bring back MapCraft! We can't login