Provide each Example with its own set of annotations

I have a use case where I'd like to be able to dynamically mark a particular scenario as generated by an entry in an Examples table as pending. This patch provides a shallow clone of the original scenario annotations object for the individual table generated scenarios such that those scenarios can then be assigned a pending annotation (or any other really) and not have it effect the rest of the scenarios from that table. Normal marking of the scenario with @Pending still causes all generated scenarios from the table to be pending.

I went with a shallow clone here because it was the easiest to implement. I'm not sure if ES5 code is acceptable. If ES3 would be preferred I can swap it out.