updated for most recent version of boto, removed dependency on cnames where possible
version bump
allow newer versions of boto and pyyaml
add version-label argument for init command
fix minor typo
environment variables are replaced in conf file

- environment variables of the form ${VARIABLE} are replaced
  with their contents before loading the configuration file -
  this is to allow keys, secrets, and passwords that should
  not be checked into source control to be referenced in
  the configuration file
fixing typo in README.md
improvements to help system

- can now execute 'ebs-deploy -h' or 'ebs-deploy --h' and not get an exception
- can also execute 'ebs-deploy help' and get a help message
removing spurious blank line
refactoring - inlining usage_and_exit method
adding forgotten file help_command.py
 adding option for termination delay to zdt_deploy

- can now specify number of seconds to wait before terminating
  the old environment - useful for allowing DNS IP cache entries
  to expire on the clients
Merge pull request #8 from adamfeuer/config-gets-keys-from-env-vars

environment variables are replaced in conf file
Merge pull request #10 from adamfeuer/zdt-deploy-termination-delay

 adding option for termination delay to zdt_deploy
Merge pull request #9 from adamfeuer/help-improvements

Help system improvements
Merge pull request #5 from davecap/init-with-version

Initialize with version label
version bump