visualize CameraInfo on rviz

a rviz plugin to visualize `sensor_msgs::CameraInfo`

![screenshot_from_2014-09-09 18 47 44](https://cloud.githubusercontent.com/assets/40454/4199702/4bc3efbc-3808-11e4-98f6-5be46cac52ae.png)
![screenshot_from_2014-09-09 19 02 23](https://cloud.githubusercontent.com/assets/40454/4199703/4bc979c8-3808-11e4-8821-52e6e8d5a5bb.png)