Pfd qml fixes

The first commit improves anti-aliaising and tells Qt that QML will take care of drawing the background. 

Without anti-aliasing
![Screen Shot 2013-04-20 at 12 00 02 PM](https://f.cloud.github.com/assets/1118185/404974/56b2531a-a9a1-11e2-96a1-551d744e6c48.png)

With anti-aliasing
![Screen Shot 2013-04-20 at 11 59 04 AM](https://f.cloud.github.com/assets/1118185/404975/56c8f93a-a9a1-11e2-84e7-540ffba4fdf1.png)



The second fixes the arrow loading problem in the QML PFD. The artwork was not reloading because the ```source``` variable was only set when the PFD was loading. The solution was to set the source variable whenever the connection status changed.

No connection
![Screen Shot 2013-04-20 at 11 52 56 AM](https://f.cloud.github.com/assets/1118185/404962/429ae5d2-a9a0-11e2-8374-116d86e7344b.png)

Handshake requested
![Screen Shot 2013-04-20 at 11 53 14 AM](https://f.cloud.github.com/assets/1118185/404959/3bbe99d4-a9a0-11e2-8b33-474c81948e32.png)

Handshake Acknowledged. Note that there is no artwork for this arrow.
![Screen Shot 2013-04-20 at 11 53 22 AM](https://f.cloud.github.com/assets/1118185/404958/33624f1a-a9a0-11e2-9e13-e59d64881183.png)

Connected
![Screen Shot 2013-04-20 at 11 53 31 AM](https://f.cloud.github.com/assets/1118185/404957/2e504324-a9a0-11e2-8944-07dc192af368.png)