Facebook iOS SDK 3.2.1 (see https://developers.facebook.com/ios/change-log-3.x/)

Summary:

Added
    Support for frictionless application requests in FBWebDialogs

Fixed
    Exception in certain request methods when a handler is nil

Reviewers: gregschechte

Reviewed By: gregschechte

Test Plan: Release Testing.
Merge branch 'facebook' into develop