make some variables of the Completion class private
make some variables of the Completion class private

dwillmer/jedi,jonashaag/jedi,tjwei/jedi,tjwei/jedi,WoLpH/jedi,dwillmer/jedi,mfussenegger/jedi,flurischt/jedi,flurischt/jedi,jonashaag/jedi,mfussenegger/jedi,WoLpH/jedi