Show list of pending charms to deploy

No one asked for this, it's just an idea I had to show a little more context of what's happening while you wait:

![deploy-queue-screenshot2](https://cloud.githubusercontent.com/assets/1768106/4051082/73295092-2d5e-11e4-84c8-fde7e3f5b1eb.png)
![deploy-queue-screenshot](https://cloud.githubusercontent.com/assets/1768106/4051083/733a56d0-2d5e-11e4-8779-0f2dd82dbfdb.png)

:coffee: :smoking: :watch: