Added licenses for third party JS libraries used by Web UI.
Added licenses for third party JS libraries used by Web UI.

Review: https://reviews.apache.org/r/66257/

jpeach/mesos,gsantovena/mesos,andschwa/mesos,kaysoky/mesos,abudnik/mesos,chhsia0/mesos,dforsyth/mesos,Gilbert88/mesos,jpeach/mesos,reneploetz/mesos,andschwa/mesos,chhsia0/mesos,kaysoky/mesos,andschwa/mesos,reneploetz/mesos,abudnik/mesos,abudnik/mesos,reneploetz/mesos,jpeach/mesos,reneploetz/mesos,andschwa/mesos,andschwa/mesos,kaysoky/mesos,kaysoky/mesos,reneploetz/mesos,jpeach/mesos,dforsyth/mesos,gsantovena/mesos,Gilbert88/mesos,Gilbert88/mesos,abudnik/mesos,asamerh4/mesos,Gilbert88/mesos,kaysoky/mesos,asamerh4/mesos,dforsyth/mesos,abudnik/mesos,Gilbert88/mesos,jpeach/mesos,andschwa/mesos,gsantovena/mesos,asamerh4/mesos,jpeach/mesos,jpeach/mesos,chhsia0/mesos,dforsyth/mesos,dforsyth/mesos,chhsia0/mesos,abudnik/mesos,gsantovena/mesos,abudnik/mesos,Gilbert88/mesos,kaysoky/mesos,dforsyth/mesos,gsantovena/mesos,kaysoky/mesos,chhsia0/mesos,Gilbert88/mesos,reneploetz/mesos,andschwa/mesos,asamerh4/mesos,asamerh4/mesos,asamerh4/mesos,gsantovena/mesos,reneploetz/mesos,chhsia0/mesos,gsantovena/mesos,asamerh4/mesos,dforsyth/mesos,chhsia0/mesos