Project shallow copy - tests to illustrate the issue

Dave,

Whilst adding a feature (separate pull request to come) I noticed that the Project code was creating a shallow copy of ````features````, so the test comparing ````features.Count```` and ````projectedFeatures.Count```` will always return true.

Not an issue for me, but thought I'd share this pull request that adds three failing tests illustrating what I think the issue is.

Cheers