Added audio.alert_device general setting

Ignore-this: 8ad81644b0244dc3d2f695ea2d8a7401

darcs-hash:20090708153807-1e3d8-1d3b1ef1f505c336a67b6801dd310bc71284c571
Properly deallocated PJSIP memory pool in core

darcs-hash:20090709135907-58103-19179e1ef45235c7af469b7bde23839b62434628