Move Project#create_from_todo to its own class

The point of this is to keep as many things out of the ActiveRecord
objects as possible and use them as just a thin database abstraction
layer.

app/controllers/todos_controller.rb

@@ -776,7 +776,7 @@ class TodosController < ApplicationController
 
   def convert_to_project
     todo = current_user.todos.find(params[:id])
-    @project = Project.create_from_todo(todo)
+    @project = ProjectFromTodo.new(todo).create
 
     if @project.valid?
       redirect_to project_url(@project)

app/models/project.rb

@@ -47,21 +47,6 @@ class Project < ActiveRecord::Base
     NullProject.new
   end
 
-  def self.create_from_todo(todo)
-    project = Project.new(:name => todo.description,
-                          :description => todo.notes,
-                          :default_context => todo.context)
-
-    project.user = todo.user
-
-    if project.valid?
-      todo.destroy
-      project.save!
-    end
-
-    project
-  end
-
   def hide_todos
     todos.each do |t|
       unless t.completed? || t.deferred?