added basic user authorization

@RichardBlair 
Updated routing, controllers, and views in adding user authentication to dickbook to match Rails 4.1.1 standards utilizing information from the following resources:

http://railscasts.com/episodes/250-authentication-from-scratch
https://github.com/rails/strong_parameters
and, of course, advice from https://github.com/RichardBlair
```
  def encrypt_password
    return unless password.present?
    self.password_salt = BCrypt::Engine.generate_salt
    self.password_hash = BCrypt::Engine.hash_secret(password, password_salt)
  end
```