When a user sends an available presence the old presence is discarded and the phone status info is lost

We are adding a phone-status element to the sessions' presences. The problem is that when a user sends an available presence the old presence is discarded and the phone status element is lost.

Two options to fix this problem:
1) Use a packet interceptor
The packet interceptor will react before the intercepted packet has been processed and is a Presence with no TO attribute or the TO attribute matches the hostname

2) Add a presence event listener
The server does not support presence event listeners but if we add this feature then it would be possible to add a listener that will be invoked when the presence of a ClientSession has been modified.