* Add 'demo' subcommand
* Add is_jug_running() function
* Fix bug in finding config files
* Improved --debug mode: check for unsupported recursive task creation
* Add invalidate() to shell environment
* Use ~/.config/jug/jugrc as configuration file
* Add experimental support for extensible commands, use
~/.config/jug/jug_user_commands.py
* jugrc: execute_wait_cycle_time_secs is now execute_wait_cycle_time
* Expose sync_move in jug.utils