Upgraded conductor graph

This updates and cleans up the conductor graph. @dwlee Only some of the code update is here, other bits got merged in the 'great sync' on thursday. Don't worry about the details too much.

* Major cleanup, got rid of all unused rosgraph code
* No more app manager in here
* Now listens to the conductor graph topic
* Shows all clients - pending, joining, uninvited, available, missing, blocking, busy and bad.
* Option for clustering by ip

Still some things to check though:

* Sanity checks for starting with no concert around.
* Do tests for all the client states above
* Filtering options - probably we want to sometimes filter the noisy ones (like busy)
* View upgrades in case it gets confusing when a whole lot of clients are around.