Clarified comments in sorter.
Clarified comments in sorter.

Review: https://reviews.apache.org/r/56349

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