Sanitizing Plist UTF8 strings #2482

I like to resolve this issue asap. I would appreciate your feedback on the solution.
I'm willing to do whatever it takes to fix this. Let me know if this is the way to do it.

Thank you, Ladi
This would break on Ruby 1.8.7, as it has no `String#encode` method. Since 1.8.7 doesn’t even have the concept of encodings and we’ll be removing 1.8.7 support in the near future, I think it’s safe to just return the `text` as-is versions below 1.9.