CLC-3830 / CLC-3835: Change title + add download link

CLC-3830: Change title in audio feed to the RSS title instead
https://jira.ets.berkeley.edu/jira/browse/CLC-3830

CLC-3835: Webcasts - Add download link in UI for audio
https://jira.ets.berkeley.edu/jira/browse/CLC-3835