Remove codec_list from audio which moved to rtp section

darcs-hash:20090807091629-58252-4cdee0ffe67d803935220c75fcd9565181db389d
Moved *_interval and outbound_proxy setting under account.sip section

darcs-hash:20090807185845-58252-984a90e8787431a79c6af3ad890726678d0b3870