Added view for contentpage to display the blocks as tabs.

I've added a view to display the blocks in a contentpage as tabs.
![bildschirmfoto-2013-07-02-um-14 38 56](https://f.cloud.github.com/assets/157533/736415/daa36678-e317-11e2-9e31-d7756009bec6.png)
@jone please take a look