Analysis API

* [x] Users should be able to index Analyses for which they are the Author or if the Topic is closed. Moderators and the Owner of the Group can index all Analyses.
* [x] Users should be able to show an Analysis if they are the Author or the Topic is either closed. Moderators and the Owner of the Group can always show a Topic.
* [x] Users should be able to create an Analysis for a Topic in a Group they belong to if that Topic is open. The Owner of the Group can always create an Analysis.
* [x] Users should be able to update an Analysis if they are the Author and the Topic is open. Moderators of the Group can update an Analysis if the Topic is open. The Owner of the Group can always update an Analysis.
* [x] Users should be able to destroy an Analysis if the are the Author and the Topic is open. Moderators of the Group can destroy an Analysis if the Topic is open. The Owner of the Group can always destroy an Analysis.