This avoids the need to use /etc/boto.cfg to change your default region before launching the bees.
Used status file to remember the chosen region.
Adding support for regions other than us-east-1 by extracting region …
…from supplied zone.
Status file is used to remember the region.
I think it's good to support alternate zones. I'm mildly concerned that this will interact badly with people who were using the bees before this change, if we were to merge it.
Going to address this as part of #19.