New Rating UI, including new UI theme, and new Feedback and ThankYou dialogs. New email acquisition behavior. New Person object sending code. Refactored all the Rating flow logic. Support for tablet and various screen sizes in rating flow.
Update .gitignore file.
Merge branch 'new_rating_flow' into message_center_v2
Refactor dialog names. FeedbackDialog -> MessageCenterIntroDialog. ThankyouDialog -> MessageCenterThankYouDialog.
Add metrics for message center intro and thank you dialogs.