A free in add_pri was ultimately the source of the grief we were having with parking. This set of changes fixes that problem, and introduces some more error messages, and puts debugs into ifdefs for what could be short-term usage. Txs to Terry W. for his help, guidance, and especially patience.

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@89474 65c4cc65-6c06-0410-ace0-fbb531ad65f3