NEW Patch for SS 3.1

This patch makes the dashboard work with 3.1.* installations and could possibly resolve issue #23.

##### Please notice:
* untested GoogleAnalyticsPanel (you can create this panel, but I don't have an account...)
* untested Section-, GridField- and ModelAdmin panels (you can create these panels, but I haven't set up any GridFields, etc on my test install)

[Click me for small screenshot](http://i.imgur.com/qdEmxA1.png)