Msgs to "local" servers, strings not sent, cleanup

- Done for Delete, End_program, restore & save persistent.
- Servers do not communicates amongst themselves.
- Unused code was cleant up in the SipServer class.
- Instead of sending strings, a slot number into the SipTable is sent to the server.

Minor fix for : Messages sent to "local" servers.

Code cleanup of sip_server

Sending slot into sip_table instead of string (persistent).