FR: Auto lock database

[IOIO72]

There should be a way or some ways to increase the security of the unlocked database.

One big issue could be, that any third person might be able to access the database, if someone leaves the Mac alone and forgot to lock the Mac.

Some ideas for options for different levels of unlock security:

• Always input master password (don't save master password)
• Timeout in minutes to forget master password: X minutes
• Use quick unlock by using the last number of characters of the master password: N characters
• Use fingerprint sensor
• ...