Facebook iOS SDK 3.13.1

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

Upgrading:
    https://developers.facebook.com/docs/ios/upgrading/
Facebook iOS SDK 3.14

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

Upgrading:
    https://developers.facebook.com/docs/ios/upgrading/
Merge branch 'upstream-master'
- reverted: disabled GCC_TREAT_WARNINGS_AS_ERRORS to support Xcode 5.1
- updated to 3.14