bufferevents cleaning



git-svn-id: http://rfc5766-turn-server.googlecode.com/svn/branches/v3.2@1706 d3c6d0af-6456-5cbd-3218-6188ca4e956b
cleaning



git-svn-id: http://rfc5766-turn-server.googlecode.com/svn/branches/v3.2@1707 d3c6d0af-6456-5cbd-3218-6188ca4e956b