Student password hash is now available at `student.key`

v0.3.3

Hashed password is now saved at `student.key`.

Added option to log in with hash of password

Now, you don't need to always log in with user password. Hash of the password can now be used as well. This is great for applications that stores password hash locally, as now they don't need to prompt for user password each time.

The hash is stored after logging in at bakalari._key.