Updated CHANGELOG for new HTTP authentication flags.
Updated CHANGELOG for new HTTP authentication flags.

Review: https://reviews.apache.org/r/50332/

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