[Asterisk-Dev] SIP presence notification updated (#3644)

[Rich Adamson]

> After months in the bug tracker, we've finally committed a lot of
> changes to the SIP Subscribe subsystem in Asterisk cvs head.
> 
> * It now works even if you reload the dial plan
> * It does not accept subscriptions to extensions without hints
> * It will terminate subscriptions if the hint does not exist
>   after a dialplan reload
> 
> To get this to work properly, you
> * Configure incominglimit for the device
> * Add a hint to the dialplan for the extension
> 
> Now, you will see if the device is online, if it is
> occupied in a call or just available for a call. This is confirmed
> to work with Polycom phones, SNOM phones and Eye-Beam.
> 
> A big thank you to everyone that have been assisting me working with
> this patch and to Kevin that solved the reload problem.

Olle,

For those of us that can't read code and have not been following
the sip changes, any chance you could provide a real example of
how to make this work properly?

Rich