[Foundation] Update CharacterSet and NSCharacterSet punctuationCharacters to more consistent naming
[Foundation] Update CharacterSet and NSCharacterSet punctuationCharacters to more consistent naming

Addresses rdar://problem/26628434 Swift3: "whitespaces"?

apple/swift-corelibs-foundation,apple/swift-corelibs-foundation,apple/swift-corelibs-foundation,apple/swift-corelibs-foundation,apple/swift-corelibs-foundation