Connect spring-security to a database table

[lafkob]

Current authentication is set up to a hardcoded username and password. This needs to be database driven.

Important inclusions:

• key derivation function for hashing
• the registration page ticket so we can get hashes/salts into the database

[StormGull]

The login page is now wired to use our data source for the username and password. It automatically hashes the password and checks it against the database value. Since we are using BCrypt, which has the salt built into the hash itself, we don't need to store the salt.

Still left to: Registration page to add a user and his/her hashed password to the database.

[lafkob]

Closing, the remaining todo is captured in #12