FreeSWITCH-mod-radius-cdr_improvement

fix minor bugs
make whitepages work if regular url not set (oops)
channel var set for area
ignore "UNKNOWN" and "UNAVAILABLE" from api


git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@15331 d0543943-73ff-0310-b7d9-9358b9ac24b2