Changed the dockerized docker command executor CommandInfo usage.
Changed the dockerized docker command executor CommandInfo usage.

This changes how we override the `CommandInfo` when launching a
dockerized executor; from `shell == true` to `shell = false`.
This means that flags are now passed directly rather than as
a long string.

i.e.
From: 'mesos-docker-executor --foo="bar" --some="thing"'
To: [ 'mesos-docker-executor', '--foo=bar', '--some=thing' ]

Review: https://reviews.apache.org/r/47215/

Gilbert88/mesos,yuquanshan/customizedMesos,yuquanshan/customizedMesos,dforsyth/mesos,verizonlabs/mesos,andschwa/mesos,kaysoky/mesos,reneploetz/mesos,andschwa/mesos,gsantovena/mesos,kaysoky/mesos,abudnik/mesos,gsantovena/mesos,chhsia0/mesos,Gilbert88/mesos,verizonlabs/mesos,craimbert/mesos,craimbert/mesos,neilconway/mesos,zmalik/mesos,gsantovena/mesos,asamerh4/mesos,Gilbert88/mesos,yuquanshan/customizedMesos,dforsyth/mesos,jpeach/mesos,reneploetz/mesos,jpeach/mesos,craimbert/mesos,verizonlabs/mesos,Gilbert88/mesos,dforsyth/mesos,zmalik/mesos,verizonlabs/mesos,reneploetz/mesos,craimbert/mesos,neilconway/mesos,zmalik/mesos,abudnik/mesos,kaysoky/mesos,jpeach/mesos,reneploetz/mesos,Aman-Jain-14/customizedMesos,andschwa/mesos,jpeach/mesos,dforsyth/mesos,kaysoky/mesos,asamerh4/mesos,gsantovena/mesos,neilconway/mesos,Gilbert88/mesos,andschwa/mesos,zmalik/mesos,Gilbert88/mesos,chhsia0/mesos,gsantovena/mesos,Aman-Jain-14/customizedMesos,asamerh4/mesos,abudnik/mesos,Aman-Jain-14/customizedMesos,asamerh4/mesos,jpeach/mesos,neilconway/mesos,reneploetz/mesos,neilconway/mesos,chhsia0/mesos,Aman-Jain-14/customizedMesos,andschwa/mesos,asamerh4/mesos,kaysoky/mesos,yuquanshan/customizedMesos,reneploetz/mesos,yuquanshan/customizedMesos,abudnik/mesos,zmalik/mesos,zmalik/mesos,yuquanshan/customizedMesos,Aman-Jain-14/customizedMesos,dforsyth/mesos,andschwa/mesos,craimbert/mesos,gsantovena/mesos,zmalik/mesos,neilconway/mesos,Aman-Jain-14/customizedMesos,verizonlabs/mesos,Gilbert88/mesos,abudnik/mesos,chhsia0/mesos,craimbert/mesos,abudnik/mesos,dforsyth/mesos,chhsia0/mesos,craimbert/mesos,abudnik/mesos,gsantovena/mesos,kaysoky/mesos,jpeach/mesos,yuquanshan/customizedMesos,reneploetz/mesos,verizonlabs/mesos,dforsyth/mesos,andschwa/mesos,jpeach/mesos,asamerh4/mesos,Aman-Jain-14/customizedMesos,asamerh4/mesos,chhsia0/mesos,verizonlabs/mesos,chhsia0/mesos,neilconway/mesos,kaysoky/mesos