Facebook iOS SDK 3.5.2

Summary:
     Bug fixes. See https://developers.facebook.com/ios/change-log-3.x/

Reviewed By: jacl

Test Plan: Release Testing.
Facebook iOS SDK 3.5.3

Summary:
     Bug fixes. See https://developers.facebook.com/ios/change-log-3.x/

Reviewed By: jacl

Test Plan: Release Testing.

@update-submodule: vendor/OCMock
Facebook iOS SDK 3.6

Summary:
     see https://developers.facebook.com/ios/change-log-3.x/

    Upgrading from 3.5
     https://developers.facebook.com/docs/tutorial/iossdk/upgrading-from-3.5-to-3.6

Reviewed By: jacl

Test Plan: Release Testing.
Facebook iOS SDK 3.7

Summary:
     see https://developers.facebook.com/ios/change-log-3.x/

    Upgrading from 3.6
     https://developers.facebook.com/docs/tutorial/iossdk/upgrading-from-3.6-to-3.7

Reviewed By: jacl

Test Plan: Release Testing.
Facebook iOS SDK 3.7.1

Summary:
    Bug fixes. See https://developers.facebook.com/ios/change-log-3.x/

Reviewed By: jacl

Test Plan: Release Testing.
Merge tag 'sdk-version-3.7.1' of github.com:facebook/facebook-ios-sdk into test-update-sdk

SDK 3.7.1
merge project settings
Merge pull request #1 from airbnb/update-sdk-3.7.1

Update to Facebook iOS SDK 3.7.1