Fixed master to properly handle status updates when multiple of them are enqueued on the slave.
Fixed master to properly handle status updates when multiple of them
are enqueued on the slave.

The master now doesn't change the latest state of a task if it has
already terminated. But it still updates the status update state and
uuid.

Review: https://reviews.apache.org/r/39873

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