Fix selection bug related to failure to clone select key vector.

By default ObjectModelNamespaceSelector holds a _reference_ to an selectKeyVector passed to its constructor. If the incoming select key vector contains more keys than are requires to resolve the namespace indicated by the path ID then the vector is cloned, and the extra keys contained in the input are removed from the selectors _own_ select key vector. So selectors have two dimenensions: resolution AND key ownership. Resolution = resolved vs. unresolved (related to select keys) and Ownership = keys-by-value vs. keys-by-reference (selector owns its own select key vector vs a reference to someone elses). 'keys-by-reference' selectors can be used within the calling context they are provided in but cannot be saved and used in other contexts. To save a selector for use in another calling context, use the new ObjectModelNamespaceSelector.clone method to create a detached 'keys-by-value' selector.