Remove TMUX support.
Remove TMUX support.

After discussion on the mailing list tmux is not used much and since it
was broken for a while remove that support.

Fixes bug 928967.

Change-Id: Iff1eea45190f4ef873c60b3563fe94359702446d

NaokiMiyata/devstack,sc68cal/devstack,upadhyay-prashant/devstack,upadhyay-prashant/devstack,LoHChina/devstack,Juniper/devstack,Mahito/devstack,nati/devstack_public,citrix-openstack-build/devstack,savi-dev/devstack,shootstar/devstacktest,neerja28/Devstack_GlusterFS,openstack-dev/devstack,nttmcl/devstack_public,r-mibu/devstack,promptworks/devstack,avvocatodemarchis/devstack,nati/devstack_public,bq-xiao/devstack,srics/devstack,ozamiatin/devstack,BSJAIN92/OpenStack,nttmcl/devstack_public,pacinete/devstack,sc68cal/devstack,Mahito/devstack,pacinete/devstack,bljgaurav/openstack-test,prithivm/branch01,mmasaki/devstack,prithivm/branch01,mssumanth/devstack,mmasaki/devstack,sstrato/devstack,samgoon/devstack,LoHChina/devstack,parul24/devstack,deepakselvaraj/devstack,ykaneko/devstack,andrewrothstein/devstack,armando-migliaccio/devstack,group-policy/devstack,nuxeh/devstack,TwinkleChawla/devstack,vishnugonela/devstack,bq-xiao/devstack,varunarya10/devstack,sequenceiq/devstack,NaokiMiyata/devstack,samgoon/devstack,olivierlemasle/devstack,yamt/devstack,richliu/devstack,HPCHub/devstack,wenhuizhang/devstack,BSJAIN92/OpenStack,openstack-dev/devstack,r-mibu/devstack,wenhuizhang/devstack,inkerra/devstack,cloudbuilders/devstack,andrewrothstein/devstack,tianweizhang/devstack,pczerkas/devstack,j4/devstack,noironetworks/devstack,ewindisch/raspi-devstack,promptworks/devstack,citrix-openstack-build/devstack,avvocatodemarchis/devstack,group-policy/devstack,HPCHub/devstack,herrsechs/devstack,virtualopensystems/devstack,bljgaurav/openstack-test,bigswitch/devstack,CloudServer/devstack,liuquansheng47/devstack,herrsechs/devstack,neerja28/Devstack_GlusterFS,JioCloud/devstack,rushiagr/devstack,ykaneko/devstack,Millnert/contrail-devstack,CloudServer/devstack,nuxeh/devstack,richliu/devstack,eharney/devstack,vishnugonela/devstack,affo/devstack,liuquansheng47/devstack,williamthegrey/devstack,varunarya10/devstack,kplus/devstack-moonshot,dirkmueller/devstack,cloudbuilders/devstack,mc2014/devstack,flavio-fernandes/devstack,eharney/devstack,affo/devstack,nawawi/openstack,noironetworks/devstack,flavio-fernandes/devstack,bswartz/devstack,costingalan/devstack,Yuriy-Leonov/devstack,CiscoSystems/devstack,atulpatil301/devstack,bigswitch/devstack,atulpatil301/devstack,kplus/devstack-moonshot,nawawi/openstack,rushiagr/devstack,vsham20/devstack,mc2014/devstack,parul24/devstack,costingalan/devstack,pczerkas/devstack,jamielennox/devstack,olivierlemasle/devstack,vsham20/devstack,ozamiatin/devstack,dtroyer/devstack,eshnil2000/devstack,tianweizhang/devstack,dtroyer/devstack,sequenceiq/devstack,savi-dev/devstack,bswartz/devstack,pombredanne/devstack,TwinkleChawla/devstack,dirkmueller/devstack,ewindisch/raspi-devstack,thomasem/devstack,pombredanne/devstack,thomasem/devstack,innodee/openstackk,mssumanth/devstack,j4/devstack