Updates for Pagination on Member Notifications

This is a pull-request for the functionality described in a [comment](https://github.com/umbraco/OurUmbraco/pull/31#issuecomment-56880594) on #31 

* Add a **Show all #### topics!** button to the pager
* Add class `TopicSolved` to solved topics (with styles)
* Sorting the results by **updated** (descending)

Should make @jbreuer and others happy :)

Reference renderings:

![c10b32a6-44f3-11e4-8607-ae074b38e06c](https://cloud.githubusercontent.com/assets/5463/5497328/d5c2de56-8710-11e4-9917-a0f82abbf3f2.png)

![c92712de-44f3-11e4-9191-51f135156e97](https://cloud.githubusercontent.com/assets/5463/5497342/f04398a6-8710-11e4-962b-b3db559a60a2.png)