Comment 22 for bug 1440111

Some of this is doable for OTA10, and some is not, so we may want to split this workload into two tickets.

OTA 10:
* Calendar notifications should not override silent mode
* Clock alarms should override silent mode
* Calendar notifications' title and icon can be changed to not denote alarms

post-OTA 10:
> Calendar notifications are not currently appearing in the notification tray within indicators and should be.
This is going to require significant work on the notification center)

Need clarification:
> Calendar Notifications are displayed for too brief a period and should conform to the same timing as other notifications.
I believe calendar notifications last for 5 seconds the same as other notifications, so clarification on this request would be helpful for me.