Save user password as a bcrypt hash

* Replace password field by password_hash
* Add User#password attribute
* Implement password hashing and verification with BCrypt mixin

db/migrate/20110809130610_add_password_hash_to_users.rb

@@ -0,0 +1,11 @@
+class AddPasswordHashToUsers < ActiveRecord::Migration
+  def self.up
+    add_column :users, :password_hash, :string
+    remove_column :users, :password
+  end
+
+  def self.down
+    remove_column :users, :password_hash
+    add_column :users, :password, :string
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended to check this file into your version control system.
 
-ActiveRecord::Schema.define(:version => 20110805201426) do
+ActiveRecord::Schema.define(:version => 20110809130610) do
 
   create_table "playlists", :force => true do |t|
     t.string   "name"
@@ -38,9 +38,9 @@ ActiveRecord::Schema.define(:version => 20110805201426) do
 
   create_table "users", :force => true do |t|
     t.string   "email"
-    t.string   "password"
     t.datetime "created_at"
     t.datetime "updated_at"
+    t.string   "password_hash"
   end
 
 end