Err when using MR and submitting bad credentials

Fixed unexpected error when using MembershipReboot.UserService and
submitting bad credentials #199
Merge pull request #201 from rklachko/mr_bad_cred_err

Error when using MR user service and submitting bad credentials
Added license headers
Merge branch 'master' of https://github.com/thinktecture/Thinktecture.IdentityServer.v3
Cleanup
Merge branch 'master' into RefreshTokens