Fix on_unit_ready()

Got it wrong and lighttpd doesn't have any mercy.
Fix str_append_data()

`void *' is more appropriate here.
Don't initialize the service before connecting
Simplify the plugin API
Formatting

No idea how this happened.
Implement idle events
Avoid spinning in a loop

This also helps reduce a lot of noice in strace.
Update the README
Identified a hot-spot
Fix the hotspot

Valgrind seems to be quite happy with it now.