OAuth 1.0 Consumers are now *much* simpler, entirely avoiding channels.

Build breaks in other projects, however.
Fixes some OAuth 1 build breaks.
Merge branch 'httpclient' into OAuthSimple
Fixes build breaks everywhere exception DNOA.AspNet.
Fixes build breaks in DNOA.AspNet
Fixes some recent regressions to get twitter.aspx working.
Applied similar redirect fixes elsewhere.
Comment fix
Removes trivial nonce store implementation from WebAPI sample.
Removes the memory crypto key store from the sample.

We now have a 'hard-coded' secret key store that trivial apps/samples may use to keep things simple until they create a database table.
Fixed up WebAPI sample so it works with anonymous clients.
Switch to use HttpClient for OAuth 2 authorized call.
Fixes bad logic that reports expired tokens incorrectly.
Removes OAuthPrincipal in favor of ClaimsPrincipal.
Merge branch 'OAuthSimple' into httpclient