added threads filter class
teardown :
   added new teardown method to BaseFilter
   stubbed with empty implementation
   changed mlogfilter to call teardown on completion of run method
conn property
   added conn property to logevent
   the property is generated for lines that match 'connection accepted' from the #<number>
Changed logline filter to match logevent.thread or logevent.conn so that the accept connection line is also printed