ClearableQueue redundant with self.close
ClearableQueue redundant with self.close

Closing the printer connection and then reopening (when the users clicks
connect) will create a new fresh MachineCom object so the queues will
start out empty.  Plus ClearableQueue was even more tied to the Queue
implementation that the current _get/_put overrides.
(cherry picked from commit e7584cd)

leductan-nguyen/RaionPi,senttech/OctoPrint,dansantee/OctoPrint,shohei/Octoprint,beeverycreative/BEEweb,nickverschoor/OctoPrint,Jaesin/OctoPrint,ErikDeBruijn/OctoPrint,foosel/OctoPrint,chriskoz/OctoPrint,Jaesin/OctoPrint,bicephale/OctoPrint,eliasbakken/OctoPrint,Skeen/OctoPrint,MaxOLydian/OctoPrint,chriskoz/OctoPrint,ErikDeBruijn/OctoPrint,dragondgold/OctoPrint,dragondgold/OctoPrint,beeverycreative/BEEweb,Salandora/OctoPrint,mcanes/OctoPrint,punkkeks/OctoPrint,eliasbakken/OctoPrint,dansantee/OctoPrint,dragondgold/OctoPrint,JackGavin13/octoprint-test-not-finished,Salandora/OctoPrint,nicanor-romero/OctoPrint,senttech/OctoPrint,foosel/OctoPrint,CapnBry/OctoPrint,nicanor-romero/OctoPrint,chriskoz/OctoPrint,ryanneufeld/OctoPrint,eddieparker/OctoPrint,shohei/Octoprint,nicanor-romero/OctoPrint,Javierma/OctoPrint-TFG,Skeen/OctoPrint,shohei/Octoprint,shohei/Octoprint,leductan-nguyen/RaionPi,foosel/OctoPrint,punkkeks/OctoPrint,bicephale/OctoPrint,bicephale/OctoPrint,Jaesin/OctoPrint,MaxOLydian/OctoPrint,Javierma/OctoPrint-TFG,Mikk36/OctoPrint,beeverycreative/BEEweb,ErikDeBruijn/OctoPrint,shohei/Octoprint,Jaesin/OctoPrint,eddieparker/OctoPrint,eddieparker/OctoPrint,eliasbakken/OctoPrint,JackGavin13/octoprint-test-not-finished,Javierma/OctoPrint-TFG,mcanes/OctoPrint,senttech/OctoPrint,foosel/OctoPrint,ryanneufeld/OctoPrint,Mikk36/OctoPrint,Skeen/OctoPrint,masterhou/OctoPrint,nickverschoor/OctoPrint,Salandora/OctoPrint,bicephale/OctoPrint,JackGavin13/octoprint-test-not-finished,Javierma/OctoPrint-TFG,MoonshineSG/OctoPrint,masterhou/OctoPrint,JackGavin13/octoprint-test-not-finished,ryanneufeld/OctoPrint,MoonshineSG/OctoPrint,leductan-nguyen/RaionPi,dansantee/OctoPrint,MoonshineSG/OctoPrint,Mikk36/OctoPrint,MoonshineSG/OctoPrint,beeverycreative/BEEweb,Salandora/OctoPrint,CapnBry/OctoPrint,senttech/OctoPrint,nickverschoor/OctoPrint,MaxOLydian/OctoPrint,mcanes/OctoPrint,ryanneufeld/OctoPrint,chriskoz/OctoPrint,CapnBry/OctoPrint,punkkeks/OctoPrint,CapnBry/OctoPrint,leductan-nguyen/RaionPi,masterhou/OctoPrint,nickverschoor/OctoPrint