Updated styles

Cleaned up a bunch of styling to tighten up the UI in the chat/activity area. This includes things like less-intrusive connect/disconnect activities, single-line messages to fit more on the page, aligned username/message bodies for easier scrolling, etc.

I'm not sure if these updates align with the vision of the project or if we should just maintain these updates in our own fork, but figured since we did the work, we might as well at least submit them. Here are before/after screenshots:

## Before

![screen shot 2014-05-07 at 3 36 22 am](https://cloud.githubusercontent.com/assets/93607/2899720/b40d5446-d5bb-11e3-850d-587ba6024b6b.png)

## After

![screen shot 2014-05-07 at 3 45 19 am](https://cloud.githubusercontent.com/assets/93607/2899721/b8aacee8-d5bb-11e3-9797-fa0a9539955d.png)

And then responsive styles as well:

## Before (mobile)

![screen shot 2014-05-07 at 3 48 42 am](https://cloud.githubusercontent.com/assets/93607/2899754/2637cf74-d5bc-11e3-9ad7-837b065edc53.png)

## After (mobile)

![screen shot 2014-05-07 at 3 48 17 am](https://cloud.githubusercontent.com/assets/93607/2899756/2db74da6-d5bc-11e3-8136-e0a4ed629f98.png)