bumped version to 1.1.6dev.
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
added threads filter class
reverted ThreadsFilter + removed teardown
removed regex match for initandlisten/mongosMain (although it may be a bit brittle now)
added some more --thread tests and fixture file for mongos
updated changes.md
no point looking at split tokens if there are less than 5 elements
moved new .conn feature to 1.1.6dev in CHANGES.
Merge branch 'master' into develop
added mtools box graphic in README.
made mtools box smaller.
cropped image further.
trimmed box again.
reduced shadow from box.
Merge branch 'develop' into bugfix-crossplatform-script-installation

Conflicts:
	mtools/mlogfilter/mlogfilter.py