Add error logger; log errors from content services and bots.
Stop content service on error.
Disable bot and update source on error.
Track errors in Source object; return unread errors on GET request.
Fix typo.
Move Source functions to Source model file.
Fix code review issues.
Fix based on code review.
Verify that bots are being reloaded on source change.
Merge branch 'develop' of github.com:TID-Lab/aggie into 1120_content_service_error_handling
Merge branch '1120_content_service_error_handling' into develop