Add an option to allow re-asking declined permissions

Add an option to allow re-asking declined permissions as mentioned in https://developers.facebook.com/docs/facebook-login/login-flow-for-web/v2.0#re-asking-declined-permissions
Merge pull request #151 from rajbdilip/master

Add an option to allow re-asking declined permissions
[RedirectLoginHelper] Extract URI filtering feature
[RedirectLoginHelper] Filter URI even if the user decline login
[RedirectLoginHelper] Make redirect login help extendable
[RedirectLoginHelper] Make the state generation extendable
[RedirectLoginHelper] make random function private
Merge pull request #150 from yguedidi/redirect-login-helper

Redirect login helper
First step to refactor response/request