Manage access visual issues

When there are more than 4 items in the `manageaccess` widget, Firefox shows too much space below the last one, whilst IE doesn't show any margin below the last one.

FF:

![screen shot 2014-03-24 at 19 18 56](https://f.cloud.github.com/assets/109850/2504266/39a8ba12-b38b-11e3-8a59-884c0a86e762.png)

IE:

![screen shot 2014-03-24 at 19 31 22](https://f.cloud.github.com/assets/109850/2504268/43a46868-b38b-11e3-8bd2-621b12615d3c.png)