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.
fixed #232 and #233.
mloginfo fix --queries when calculating 95% percentile
added coordinate operator and geopoint operator to mgenerate.
added --y-limits option to specify min and max limits on the y-axis. This fixes #214.
renamed parameter to --ylimits (to match --yaxis).
imported wrong file for date-util dependencies in testing.
checking for version before accessing dblclick event in matplotlib.
fixed bug when UTZ offset is 00:00. Fixes #241.