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.
Facebook iOS SDK 3.8

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

    Upgrading from 3.7
     https://developers.facebook.com/docs/ios/upgrading-from-3.7-to-3.8/

Reviewed By: chrisp

Test Plan: Release Testing.
Update project file deployment target to iOS 7 for 64-bit builds.

Reviewed By: chrisp

Test Plan: Built via XCode 5.
Facebook iOS SDK 3.9

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

Upgrading from 3.8
     https://developers.facebook.com/docs/ios/upgrading-from-3.8-to-3.9/

Reviewed By: jacl

Test Plan: Release Testing.

@update-submodule: vendor/OCMock