Modified AudioStream to new core audio framework

darcs-hash:20090629124103-58103-f702a56106f7ab9f9c3b0113d52fc9594d0e1ec6
Removed old internal conference bridge component from sipsimple.core

darcs-hash:20090629124242-58103-5ec4f8449b32cd744b9d0cd852e4decabb143448