Better cookie management

Leverage aeroger-ios-http, aerogear-ios-oauth2 to provide cookie management.
For our community tuzonghua:
Better cookie management to support multiple accounts - Some services (like Google) provide an account picker for a user to choose from. This is a much better UX. However, not all OAuth2 providers are as cool as Google. For these providers, you cannot currently sign into multiple accounts using the OAuth2 library unless you clear cookies before the embedded web view is presented. Will be working on a solution to do this.