Add initial modifications to the calendar events feed, adds dates

Add startDate and endDate to the feed initially. Next step will be to check for a more proper namespace and format for the date.
Use RSS 1.0 events spec for start date and end date

http://web.resource.org/rss/1.0/modules/event/
Correct syntax in ev:enddate
Add event namespace to feed header
Format startdate and enddate as expected
Merge pull request #1 from washingtonstateuniversity/add-rss-dates

[PR] Add RSS startdate and enddate for events