oai_dc metadata_prefix has non DC tags

[ajrbyers]

Is your feature request related to a problem? Please describe. The following tags are not strictly DC:

 <dc:volume>7</dc:volume>
 <dc:issue>1</dc:issue>
<dc:journalTitle>
 <dc:articleTitle>
 <dc:fullTextUrl>/article/id/31777/</dc:fullTextUrl>

Describe the solution you'd like If an end user required these, we should create them a custom metadata prefix and template, and return oai_dc to its natural state.

[joemull]

To fix at the same time:

• [ ] Make sure to escape invalid characters in XML, like &. A user reported this showing up in their feed: <dc:format.extent>p. 1 & p. 48</dc:format.extent>