contrib/scripts/autosupport: Update for Asterisk 13

This patch adds some minor tweaks for autosupport to update it for Asterisk 13.
This includes:
* Finally removing most references to Zaptel
* Adding support for some additional 'core' commands, and fixing nomenclature
  that generally hasn't been used for some time
* Adding some PJSIP/SIP commands to gather endpoints/peers and active channels

Change-Id: Ic997b418cbd9313588b6608e50f47b0ce6f4f1f1
(cherry picked from commit 9fc9777f)