CasCopier fails to copy subtypes of string properly

I broke the cas copier part of feature copies by not coding the test for string copying to include subtypes of strings. Fix this, and also, add check that throws a runtime exception if you attempt to copy a feature between two different CASs having different type systems, where the range name of the feature in the first Type System != the name in the 2nd. Without this check, it could copy a String feature to an integer feature, resulting or visa versa.