[turba] standard Turba attribute names, particularly '__uid'

[Adam Tauno Williams]

> - What is a 'freebusyUrl', and will my users find it useful?

Only if they are using a calendar client that understands Free/Busy.
Free/Busy is a standard way of retrieving another agent's availability.
So if you want to have a meeting with A, B, and C, your can retrieve
there free/busy, overlay them, and see what blocks of time all three
appear to be available.

Usually F/B works like a URL, you do a GET from the URL to retrieve
their F/B in a standard iCalendar file (although some clients like
Outlook use an XML format).

http://en.wikipedia.org/wiki/Icalendar#Free.2Fbusy_time_.28VFREEBUSY.29