Bump version 0.5.0b1
run_pipeline.py: Limit concurrent to 20. Warn above 6.

Closes ArchiveTeam/seesaw-kit#65
Add overall task indicators/counters to the top of the project status page.
Add stop requested/canceled events to pipeline.

Also modify the default runner to trigger said events.
Merge branch 'anthonyeden-dev-MasterTaskList' into development

Conflicts:
	seesaw/__init__.py
Merge branch 'stop-events' of https://github.com/yipdw/seesaw-kit into yipdw-stop-events
Merge branch 'yipdw-stop-events' into development
warrior ui: Use less bold and size on "Task Summary"
warrior ui: Move checkboxes into project area to make header less busy.
warrior ui: Fix checkmark being repeated on subsequent proejcts.
warrior ui: Dim the tasks in summary if 0.
warrior ui: Support broadcast messages.

Closes ArchiveTeam/seesaw-kit#8

Edit projects.json in warrior-hq with a key "broadcast_message".
Merge branch 'development'
Release version 0.5