Added refresh tokens support
Added support for Android, consistency with other mobile SDKs, etc.
Updating impl of device id provider based on feedback
Fix for if condition requiting refresh_token param when refreshing
More CR changes. Improved offline_access check and added scope to method params
Updated Details.md GettingStarted.md and README.md
Merge pull request #6 from auth0/refreshToken

Support for RefreshToken, RenewIdToken and token exp validation for Android and iOS