mod_ping_muc: Delay ping a configurable amount of time If a server is restarting, checking immediately before it has a chance to complete its restart and get ready would often fail, preventing the possibility of transparent restarts as supported by Prosody's mod_muc. Reconnecting immediately when a connection is closed for being idle, or because the remote server is trying to reclaim some resources, is also counter-productive as the connection may fail. Also, if there is some Internet routing problem affecting s2s, it may help to wait a bit before checking, in case the problem resolved itself in the mean time.

This module logs events where more than a certain amount of CPU time was
spent.

``` lua
log_cpu_threshold = 0.01 -- in seconds, so this is 10 milliseconds
```

Uses the Lua
[`os.clock()`](http://www.lua.org/manual/5.2/manual.html#pdf-os.clock)
function to estimate CPU usage.