Fixed to match Credential API refactoring.
Merge branch 'v.next' into dom/api_credential_refactoring
Renamed GeodatabaseFeatureTable to ArcGISFeatureTable
Merge branch 'v.next' of https://github.com/Esri/arcgis-toolkit-dotnet into v.next
Merge branch 'v.next' into dom/api_credential_refactoring
Merge branch 'v.next' into dom/issue65_SignInDialogWinPhone
Accommodate to Credential API changes.
Add WinPhoneChallengeHandler.
Support for Credential storage.