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

Note, api.openstreetmap.org API url currently can not do OAuth 2 handshake. See openstreetmap/operations#951 (comment)
You can split the www. base URL and api. API url. See osmlab/osm-auth#123 (comment)

[codemasher]

Hey, thanks for the notice! I'll look into this as soon as i can, but it might take a while to end up in a release as there are further changes down the (package) line I'll have to clean up first.

[danieldegroot2]

No problem. :-)

[codemasher]

OSM OAuth2 support has been added in 4647553. I'll leave the OAuth1 client for now as it is still active.