Add view for history of texts with a user phone #

Part of the internal dashboard, can be accessed through the `/incoming` view by clicking on a phone number (see below) or by simply going to the URL `/internal/phone-numbers/14151112222` (dummy phone number there)

## Link from incoming page
![screen shot 2014-12-02 at 3 32 29 pm](https://cloud.githubusercontent.com/assets/994938/5273229/b3bad41e-7a39-11e4-872a-c9cef9b1e1c4.png)

## View of history
![screen shot 2014-12-02 at 3 35 37 pm](https://cloud.githubusercontent.com/assets/994938/5273246/d11153b2-7a39-11e4-90c0-9ca781cbeccd.png)

Closes #16