Dagobah

* Added soft (SIGTERM) and hard (SIGKILL) timeouts to Tasks
* SQLite database migrations are now automatically handled by Alembic
* Added job-level JSON import and export
* Added Dagobahd.auth_disabled config key
* Single-user auth can now be disabled through the app config
* Updated Flask-Login to 0.2.6

* Added single-user auth mechanism
* Added Dagobahd.app_secret and Dagobahd.password config keys
* Missing config keys will now be replaced by defaults and place a warning in the log file and stdout
* Failed tasks can now be restarted before all running tasks complete

* Fixed broken install due to incorrect reference to standard log file
* Added missing requirements for install and for running tests