Backend updates

Improvements

• Game worlds list ("departure board") added to AirwaySim website front page.
  
  
• Major component change to the core website: Font Awesome icons changed to new Web Awesome component library, allowing easier development of unified UI elements in the future.
  
  
• Sim build version, and page load speed information is now also visible to logged-in users at the site's footer (as "nice-to-know" info, and in case of any problems).
  
  
• A few minor technical improvements made to user's login session handling for better loading times.
  
  
• Upgraded our local development environment to a new software stack, and implemented a set of new project management tools.
  
  
• Some internal database selection logic changes made for better security/configurability.

Fixes

• Fleet Commonality Calculator failed to work if selected engine had internal ID number >1000 (misconfiguration).
  
  
• Airline HQed in the Netherlands Antilles was unable to open additional bases in mainland NL.
  
  
• Base Airports page did not show the clarifying text that French (mainland) based airlines could open bases also in the French overseas departments.
  
  
• Minor layout fixes to the main navigation structure.