[Dev] Minor content model change today

[Bryan Stearns]

Last week, I'd added UI in the detail view for CalendarEvent items' 
"transparency" attribute; Katie pointed out that this attribute's 
enumerated values had changed (they're now "FYI", "Confirmed", and 
"Tentative") so I updated them in my most recent checkin (just now).

So, if you happen to have set the "show as" field on any of your 
calendar items, weird things may happen unless you --create a new 
repository. (If you didn't change this value on any of your items 
manually, you don't need to do this: another bug, just fixed, wasn't 
setting an initial value on this field.)

...Bryan