- General style and organization improvements
- Convert license type selector to controlled component
- Instead of trying to return the right description and URL directly
from the components, keep the view simple and compute the description
and URL at submit time.
Before, they were stored in one data structure called
this.state.metadata that was supposed to contain (more or less) all the
metadata for the publish, but this was unwieldy and possibly causing
unnecessary updates because not all of the metadata fields correspond
directly to fields in the interface.
