TS-4196: Memory leak from main_thread on shutdown
TS-4196: Memory leak from main_thread on shutdown

This closes #467

vmamidi/trafficserver,pbchou/trafficserver,chenglongwei/trafficserver,davidbz/trafficserver,clearswift/trafficserver,vmamidi/trafficserver,rpufky/trafficserver,persiaAziz/trafficserver,taoyunxing/trafficserver,duke8253/trafficserver,PSUdaemon/trafficserver,pbchou/trafficserver,bryancall/trafficserver,SolidWallOfCode/trafficserver,clearswift/trafficserver,clearswift/trafficserver,bryancall/trafficserver,reveller/trafficserver,duke8253/trafficserver,persiaAziz/trafficserver,clearswift/trafficserver,SolidWallOfCode/trafficserver,chitianhao/trafficserver,rahmalik/trafficserver,persiaAziz/trafficserver,reveller/trafficserver,dyrock/trafficserver,rahmalik/trafficserver,reveller/trafficserver,dyrock/trafficserver,taoyunxing/trafficserver,chitianhao/trafficserver,clearswift/trafficserver,rpufky/trafficserver,bryancall/trafficserver,pbchou/trafficserver,clearswift/trafficserver,persiaAziz/trafficserver,PSUdaemon/trafficserver,rahmalik/trafficserver,davidbz/trafficserver,chitianhao/trafficserver,chitianhao/trafficserver,reveller/trafficserver,persiaAziz/trafficserver,taoyunxing/trafficserver,dyrock/trafficserver,pbchou/trafficserver,davidbz/trafficserver,taoyunxing/trafficserver,clearswift/trafficserver,duke8253/trafficserver,chenglongwei/trafficserver,davidbz/trafficserver,pbchou/trafficserver,davidbz/trafficserver,vmamidi/trafficserver,dyrock/trafficserver,reveller/trafficserver,chenglongwei/trafficserver,rahmalik/trafficserver,taoyunxing/trafficserver,PSUdaemon/trafficserver,duke8253/trafficserver,chitianhao/trafficserver,PSUdaemon/trafficserver,davidbz/trafficserver,reveller/trafficserver,rpufky/trafficserver,duke8253/trafficserver,reveller/trafficserver,chitianhao/trafficserver,chitianhao/trafficserver,PSUdaemon/trafficserver,taoyunxing/trafficserver,rahmalik/trafficserver,reveller/trafficserver,duke8253/trafficserver,PSUdaemon/trafficserver,rpufky/trafficserver,persiaAziz/trafficserver,vmamidi/trafficserver,reveller/trafficserver,taoyunxing/trafficserver,chenglongwei/trafficserver,rahmalik/trafficserver,rahmalik/trafficserver,SolidWallOfCode/trafficserver,dyrock/trafficserver,taoyunxing/trafficserver,chenglongwei/trafficserver,duke8253/trafficserver,bryancall/trafficserver,pbchou/trafficserver,PSUdaemon/trafficserver,SolidWallOfCode/trafficserver,chenglongwei/trafficserver,rpufky/trafficserver,rahmalik/trafficserver,rpufky/trafficserver,dyrock/trafficserver,chenglongwei/trafficserver,PSUdaemon/trafficserver,bryancall/trafficserver,bryancall/trafficserver,rpufky/trafficserver,dyrock/trafficserver,SolidWallOfCode/trafficserver,rpufky/trafficserver,vmamidi/trafficserver,SolidWallOfCode/trafficserver,SolidWallOfCode/trafficserver,rpufky/trafficserver,taoyunxing/trafficserver,clearswift/trafficserver,PSUdaemon/trafficserver,vmamidi/trafficserver,clearswift/trafficserver,chenglongwei/trafficserver,persiaAziz/trafficserver,rahmalik/trafficserver,persiaAziz/trafficserver