server: Allow handlers to fail init

If a handler fails its init, we don't want to invoke its callbacks.

This change adds a flag to struct handlers, to indicate whether a
handler is active (ie, init() has returned success). Only active
handlers are used.

We also change the handler list output to indicate which are active.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
2 files changed