Added option for launching slaves as spot instances.
Added option for launching slaves as spot instances.

git-svn-id: 03d7800a49d8905ef4fbcc296184319e19243493@1132325 13f79535-47bb-0310-9956-ffa450edef68

kaysoky/mesos,zmalik/mesos,gsantovena/mesos,andschwa/mesos,reneploetz/mesos,enachb/mesos,pwendell/mesos,samwhitlock/mesos-monitoring,reneploetz/mesos,neilconway/mesos,samwhitlock/mesos-monitoring,abudnik/mesos,craimbert/mesos,chhsia0/mesos,woggle/mesos-old,andschwa/mesos,neilconway/mesos,yuquanshan/customizedMesos,pwendell/mesos,gsantovena/mesos,dforsyth/mesos,yuquanshan/customizedMesos,samwhitlock/mesos-monitoring,chhsia0/mesos,abudnik/mesos,craimbert/mesos,Aman-Jain-14/customizedMesos,charlescearl/VirtualMesos,zmalik/mesos,yuquanshan/customizedMesos,samwhitlock/mesos-monitoring,Gilbert88/mesos,dforsyth/mesos,kaysoky/mesos,enachb/mesos,verizonlabs/mesos,zmalik/mesos,Gilbert88/mesos,jpeach/mesos,chhsia0/mesos,craimbert/mesos,chhsia0/mesos,jpeach/mesos,neilconway/mesos,abudnik/mesos,wickman/mesos,woggle/mesos-old,asamerh4/mesos,charlescearl/VirtualMesos,woggle/mesos-old,abudnik/mesos,wickman/mesos,abudnik/mesos,woggle/mesos-old,pwendell/mesos,woggle/mesos-old,andschwa/mesos,Aman-Jain-14/customizedMesos,verizonlabs/mesos,gsantovena/mesos,andschwa/mesos,charlescearl/VirtualMesos,wickman/mesos,neilconway/mesos,zmalik/mesos,asamerh4/mesos,zmalik/mesos,enachb/mesos,pwendell/mesos,kaysoky/mesos,craimbert/mesos,Aman-Jain-14/customizedMesos,kaysoky/mesos,jpeach/mesos,asamerh4/mesos,Gilbert88/mesos,reneploetz/mesos,asamerh4/mesos,enachb/mesos,jpeach/mesos,reneploetz/mesos,yuquanshan/customizedMesos,neilconway/mesos,gsantovena/mesos,dforsyth/mesos,gsantovena/mesos,charlescearl/VirtualMesos,wickman/mesos,Gilbert88/mesos,Aman-Jain-14/customizedMesos,zmalik/mesos,Aman-Jain-14/customizedMesos,dforsyth/mesos,gsantovena/mesos,asamerh4/mesos,andschwa/mesos,charlescearl/VirtualMesos,dforsyth/mesos,woggle/mesos-old,neilconway/mesos,chhsia0/mesos,enachb/mesos,Gilbert88/mesos,neilconway/mesos,Gilbert88/mesos,dforsyth/mesos,verizonlabs/mesos,woggle/mesos-old,charlescearl/VirtualMesos,jpeach/mesos,abudnik/mesos,enachb/mesos,pwendell/mesos,charlescearl/VirtualMesos,charlescearl/VirtualMesos,pwendell/mesos,Gilbert88/mesos,pwendell/mesos,wickman/mesos,jpeach/mesos,asamerh4/mesos,verizonlabs/mesos,samwhitlock/mesos-monitoring,Aman-Jain-14/customizedMesos,andschwa/mesos,chhsia0/mesos,andschwa/mesos,chhsia0/mesos,reneploetz/mesos,Aman-Jain-14/customizedMesos,verizonlabs/mesos,woggle/mesos-old,samwhitlock/mesos-monitoring,craimbert/mesos,dforsyth/mesos,verizonlabs/mesos,yuquanshan/customizedMesos,craimbert/mesos,pwendell/mesos,craimbert/mesos,pwendell/mesos,charlescearl/VirtualMesos,yuquanshan/customizedMesos,abudnik/mesos,wickman/mesos,reneploetz/mesos,kaysoky/mesos,gsantovena/mesos,enachb/mesos,wickman/mesos,yuquanshan/customizedMesos,jpeach/mesos,asamerh4/mesos,reneploetz/mesos,kaysoky/mesos,kaysoky/mesos,verizonlabs/mesos,woggle/mesos-old,zmalik/mesos