New Bar widget

Basically what the title says. Here is a new widget, a bar-style display for feed values.
![bargraph 1](https://f.cloud.github.com/assets/1401239/2241112/cbe854b4-9cc0-11e3-862e-f8be99fd4192.png)

It's quite configurable. The position of the numeric quantity, as well as the number of graduations (if enabled) is broken out to the config window, as is colour.
![bargraph 2](https://f.cloud.github.com/assets/1401239/2241111/cbd9d63c-9cc0-11e3-9292-a56beaca18c7.png)