ibuf is just too confusing since there is also the 'struct ibuf'.

This is to help amused-web. Change the ctl to send an extra STATUS after a MODE change to preserve the behaviour.

libevent is a very cool library, I like its APIs and enjoy using it. However, for amused it is maybe a bit too much since it doesn't deal with too many file descriptors. Amused only needs to monitor one fd for the player process and the currently connected clients. Given that it runs per-user locally, having more than a dozen of fds open is very, very rare.

used @openbsd.org initially by mistake and got copied around in most files. Since this has nothing to do officially with the OpenBSD project, use my own email address.

The monitor mode now has access to some additional information other than just the name of the event. The `mode' and `seek' events now report the mode status and the position/duration respectively, allowing consumers of `amused monitor' to show correct and coherent information. It helps in particular applications like `amused-monitor' (in contrib/) that show a progress bar for the current song. Before, they had to run their own timers and periodically synchronize using `amused status', now they can just update the state in the same `amused-monitor' event loop.

it didn't send the IMSG_CTL_COMMIT final message so it would get stuck. This also makes 'amused flush' redundant since it's possible to 'amused load </dev/null'.