Description of problem:
When pulseaudio dies and restarts (or simply gets restarted), the gnome-volume-control-applet will lose it's connection to the daemon and won't attempt to connect to the new pulseaudio instance.
This renders the applet and the volume control keys on the keyboard/laptop useless.

Version-Release number of selected component (if applicable):
- pulseaudio 0.9.15
- gnome-volume-control-applet 2.26.0

How reproducible:
Always.

Steps to Reproduce:
1. Play some sound and confirm that you can regulate sound volume through the applet and (if applicable) your function keys.
2. Stop playing sound and restart pulseaudio (i.e. by executing pulseaudio -k && pulseaudio -D).
3. Play some more sound and notice that the volume applet and your function keys have become useless.
  
Actual results:
The applet/function keys become useless.

Expected results:
There are a few ways this could be handled:
1. The applet falls back to controlling ALSA sinks.
2. The applet disables itself (i.e. grays out the volume slider and the OSD that appears when you change the volume via a function key) and waits for a new pulseaudio instance to connect to.
3. The applet tries to restart pulseaudio itself.

It could also display a notification to inform the user that pulseaudio has crashed/is not responding.

Additional info:
None.