Adds Ignidata to Powered by Mesos list.
Adds to and alphabetizes list of software frameworks on Powered By page.
Updates link to Aurora documentation on docs home.
Fixed the flaky Os.killtree test.

Review: https://reviews.apache.org/r/17558
Sped up tag and vote scripts by not compiling the whole of mesos.

Review: https://reviews.apache.org/r/17598