Varying solutions to issues and updates

This merge request will:

• update sql/schema.sql to account for all possible ticket statuses
• correct some build issues in docker/Dockerfile solving #22 (closed)
• add a rule to config/nginx/nginx.conf which solves issue #15
• correct two sql queries in src/lib/moderation/Discussions.php to solve issue #20 (closed)
• update the ticket queue page to differentiate between ticket states
• solve #23 (closed) by adding the 'extras' field to the level creation function