Improve seeding the database.

[russtoku]

This PR:

• Adds new fixtures to streamline seeding the database and eliminate manually creating an administrative user.
• Streamlines initializing and seeding the database.
• Enables minimal security for Elasticsearch to eliminate warning messages about this.
• Updates commands to run for Quick Start and info about administrative user.
• Fixes the link to About in the header to take the user to the About information.
• Removes data/seed/load_fixtures.sh script because it is no longer needed.