Consistency in use of sell/share/track/target terminology

[j-br0]

On the call last week, @michaelkleber suggested we revise the spec and the Legal and Implementation guide to be more consistent in their use of the terms "sell," "share," "track," "use for targeted advertising," &c. While the spec is designed to be flexible and to be used to implement statutes with different wording --- and while we do not need to get consensus on precise definitions of each of these terms (since they are likely to be defined differently in law anyway) --- we should review the documents to see if there are places where terms should be used differently or more consistently.