Updates and fixes

• Replaced gunicorn with uWSGI. The default ports for the deployment tools are
  now standard HTTP(S) ports.
• Improved handling of containers, which now behave atomically.
• Improved management of uploaded blueprints. Better validation of blueprints
  discovers early a wider range of blueprint faults.
• Updated API to move most of actions to container resources instead of
  blueprint resources. Some of frequently used blueprint resources are still
  available for backwards compatibility, but internally they are mapped to
  actions on a container.
• Switched to OpenAPI documentation in Swagger.
• Better error reporting in API and on GUI.
• Containers are now able to indicate if they are busy processing a task or
  idle.
• Improved installation procedure for Cloudify 3.4.0
• Unify the naming schemes of the tools: Dashes instead of underscores for
  configuration optimization support.
• Improved unit tests and added deployment tests.
• Used upstart jobs for all services.
• Enabled a debug mode, which opens celery flower on port 5555.