Improve Administrator Panel

Significant functional and display improvements to charity administrator panel

![adminpanel](https://cloud.githubusercontent.com/assets/8646429/5247704/cd13751c-7942-11e4-8900-5966f2a06cb4.gif)

now hat these are all nice methods on `availability`, maybe just pass in that on instance variable instead of these 3 and access the methods in the view?