Programmatically build the storm.yaml file

Rather than hard-coding a bunch of options in the template (and making it necessary to override the template to remove an option), just build the file directly from the attributes.

Note that I removed `local_mode_zmq` because it wasn't actually in the template in the first place.

I also made what should be an inconsequential change to how the nimbus_host's fqdn gets stored.

I apologize for lumping these two commits into one PR, it was mainly for my own sanity, and because this is actually a cherry-pick from our own heavily-developed fork, and I didn't want to land myself in merge-hell trying to re-do all of my work on the old attribute file layout.

Please let me know if you have any questions/comments/concerns and I will try to work through them!

/cc'ing my cow-orker @jeffbyrnes