Don't load flights when returning an HTML page
Redirect to its page after adding a flight

When you add multiple flights, it doesn't redirect you.
Fix it failed to delete a flight
Don't add records while not flying
Use deleteCascade
Add a Show instance to WorkspaceFlight
Let persistent-template library generate ToJSON and FromJSON instances
Don't add Vary header

Now that yesod itself adds it.
Fix it included flights in other days in the candidates when adding a flight to a workspace
Remove a filename extension from its name when adding a flight