Changing Publisher/PublisherRole element

[sroosa]

In the controlled vocabulary review, there has been a lot of discussion about the inappropriateness of the term publisher for AV related content, especially when the vocab terms are not only about who publishes, but also who distributes, hold the rights, etc.
This is a vocab issue in that we want to have more appropriate terms.
This is a documentation issues in that we want to define what actually should go in the publisher/publisherRole elements.
This is a schema issue in that we think a element name change might be appropriate.