Change console req/response format, add unit tests
Change the format of JSON requests and replies for getting a server console over VNC. Fix the cloud command-line tool to understand the new format. Add unit tests for api/actions.py:get_console(). Add a quick-n-dirty method of detecting if we're running unit tests in settings.py.dist and set TEST accordingly. If TEST is used, the API implementation sets dry_run when creating servers in the backend and assumes mock replies from it.