Fixed Mesos containerizer to set container FETCHING state.
Fixed Mesos containerizer to set container FETCHING state.

If the container state is not properly set to FETCHING, Mesos agent
cannot detect the terminated executor when the fetcher times out.

Review: https://reviews.apache.org/r/49650

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