Version 1.1.0.1

Requirement:
1. Support pin/unpin my agenda to start screen as a secondary tile.
2. Support Standard tile for wp7.1 users and Iconic tile for wp7.8 or
wp8 users

Work:
1. Month name icon images are added to the solution to support wp8
Iconic tile（English and Chinese version are both available.）.
2. GetNextIconicCalendarNode method is added to CalendarGroup.xaml.cs to
compute the  node that will be displayed on the Iconic tile.
3. IconicDisplayTIme is added to CalendarNode to support display the
time of the node.

Remaining work:
1. Unpin secondary tile when a user signs out or it fails to auto log
in.
2. Update standard tile background image when user's avatar image is
changed.
3. Use TileSchedule to update live tile.