The fix to the build break in Swift 2.1

[jychunyih]

Have a fork and made a quick fix, check here: https://github.com/jychunyih/SwiftData/blob/master/SwiftData.swift, or get the code in my fork: https://github.com/jychunyih/SwiftData.

[RegisStGelais]

I gave the extension solution many times in the issues but ryanfowler do not seams to be folowing this project anymore.