Notification count fixes

Supports the new format for push notifications

The UI counter-part of https://github.com/oaeproject/Hilary/pull/1023
When I upload a bunch of files and share them with a user at the same time, the activities don't seem to be coming in aggregated and they are added to the notifications widget individually when that widget is already open:

![screen shot 2014-09-12 at 11 20 27](https://cloud.githubusercontent.com/assets/109850/4248669/a6076acc-3a69-11e4-86cf-962341588980.png)