Did the pubsub one a long time ago, but added a frisbee one as well.

The pubsub dissector has not been tested in its wireshark 1.8 incarnation,
I just converted it from the 1.2.10 version and made sure it compiled.
The frisbee dissector just supports the base UDP protocol (not the TCP
master server protocol) and doesn't implement wireshark conversations.

This last few commits were the result of a two-day trip into the weeds.
This started out as getting a hack shared 10Gb LAN working on the new 820
nodes. Then I decided to test it out by running frisbee at high bandwidth
over that LAN. Next thing you know, I'm out in the fields, looking at
frisbee traces and tweaking Linux sysctls...