cabbage-bundle-list-mode for display bundles

I found the `cabbage-list-bundle` function at the weekend, but wasn't that happy how it was displayed. 

I realized that `list-buffers` or `list-processes` display really nice table like lists, so I went a bit into the code and documentation and tried to realize something in the same manner for cabbage.

The `File` column is defined as `follow-link` and is clickable, so you get straight to the `bundle.el` file.

@senny what do you think?

![Cabbage Bundle List](http://i.imgur.com/pRMYxs9.png)
I think this function is way too complicated for what it's trying to achieve. Shouldn't we be able to get the same result in a single loop like so:

```lisp
(mapcar (lambda (e) 
           (cons e (if (cabbage-bundle-active-p (intern e)) "active" "inactive"))) 
  (cabbage-bundles--list-available))
```

Example currently misses the `build-tabulated-row` stuff but that should be trivial to add.