Prevent unnecessary database records

Currently the module will write database records to the database for both locked and unlocked fields. There's really no reason to store the unlocked records (that I can think of). This can also lead to a lot of unnecessary database records for the unlocked fields. If you have a form with 10 lockable fields, saving that form creates 10 records regardless of lock status (for every entity). If we omit the unlocked fields, there are only database records when a lock is made.