[click] hot-swapping at userlevel

[Eddie Kohler]

Hi all,

User-level Click now supports hot-swapping configurations. If you run
'click' with the '-R/--allow-reconfigure' option, then Click will provide a
writable 'hotconfig' handler. You can connect to a ControlSocket and write
a configuration file to the 'hotconfig' handler, thus changing the router's
configuration.

Normally this would boot you right off the ControlSocket! But ControlSocket
and ChatterSocket now support hot-swapping too; so if the new configuration
has a ControlSocket with the same name and parameters (and that has RETRIES
set to 1 or more), you'll just keep talking to the ControlSocket as if
nothing had happened.

Anyway, let me know if you have problems.
Eddie