Code review comment for lp://staging/~jamesh/bzr-dbus/kill-broadcast-daemon

This branch gets rid of the need for a separate broadcast daemon. Instead, "bzr serve" instances advertise their prefix mappings directly over the bus via signal broadcasts. They can also readvertise themselves on request to handle the case where the server starts before the signal receiver.

Similarly, commands that update branch tips now send broadcast signals over the bus directly rather than performing a method call to the broadcast daemon and having it broadcast the signal.

The lan-notify code has been updated to handle the direct signal broadcasts. The possibility remains to support fixed prefix mappings by getting lan-notify to load them on startup from a configuration file.

One out-of-tree user of the bzr-dbus signals is bzr-gtk's notification icon code. It has already been updated to handle signals from any source, so works correctly with and without this patch.