Allow app__main to shrink when app__right-col is expanded

Currently when the width is less than 1500px the app__right-col is absolutely positioned which causes the app__main to display behind it when it is expanded. 

This PR removes the absolute positioning which allows the app_main to shrink to fit when expanding app__right-col

## Before
![before](https://f.cloud.github.com/assets/200528/1050401/4da9e768-10b9-11e3-9d61-295f5aadebbf.png)

## After
![after](https://f.cloud.github.com/assets/200528/1050400/4dacdd38-10b9-11e3-991b-4e590c843784.png)