Some of the constants needed for management of secure items in macOS and iOS contexts have been around for a while but were never added to security-framework-sys. Others are there but are marked with macOS features much higher than they need to be.

This is a request to update the following constants:

• fix version: kSecAttrSynchronizable (since macOS 10.9)
• add kSecAttrSynchronizableAny(since macOS 10.9)
• add kSecUseAuthenticationUI (since macOS 10.11)
• add kSecUseAuthenticationUISkip (since macOS 10.11)

I will submit a PR that does this.