Adding scrollbars to config panels

The config options are too long to fit on 1366x768px and below resolutions.

This commit adds an _(at moment)_ vertical scrollbar to the options list.
So, we can now happly scroll through each setting.

![before](https://f.cloud.github.com/assets/320460/54597/285ba814-5a9a-11e2-80e4-38b477201d46.png)

![after](https://f.cloud.github.com/assets/320460/54599/2fa11528-5a9a-11e2-911f-a6f1d5ac60aa.png)