Automatically clean up the database

[tannn]

The database can become really large as time goes on. Some measures may need to be added to reduce its size automatically by using adjustable settings, such as:

• Automatically removing scores of inactive users
• Saving only the top x players
• Option for only keeping stats for a year

(The pruning will take place only once a day, at a specific interval)

It may also be wise to split the database into multiple files, such as one for player scores and stats and another for questions. Splitting the database into multiple files has a higher priority over the other options listed.