Fix to not ignore testing profile connection info

-RN
This fixes a bug where if using a testing profile, TempJobs would
attempt to connect to DOCKER_HOST instead of the domain or endpoint
specified in the profile.

Also added comments to the create() method to make the logic more
clear.
Do not set container hostname

Docker 1.3 seems to not like hostnames that
exceed 17 characters. We also don't seem to need it
Log "Using profile" as info instead of debug

I usually log at info level because debug is noisy, but I'd
still like to see which profile I'm using.
Fix deregister to continue when things are missing

-RN
Fix for Helios to successfully deregister hosts when they are deleted.