Selection of individual properties in [ATOM] should not include property name

Currently, the example in Section 10 of [ATOM] implies that when selecting a single property (i.e., ~Customers('ALFKI')/FirstName), the payload would contain the name of the property in the d: namespace:

<Title xmlns="http://schemas.microsoft.com/ado/2007/08/dataservices">CEO<Title>

This implies that what is represented is a property with a given name, which is not the case; what should be represented is the value of the property, which is independent of the property itself (and can thus be used, for example, in passing as a parameter to an action). This is also inconsistent with how a function that returns a single property is represented, and is inconsistent with the JSON format (which represents this as a name/value pair with the name "value").

We should specify that an individual property is serialized in ATOM as an element named "value" in the odata metadata namespace.