Minor tutorial fixes

I done the tutorial and found some minor issues with the code examples.

I done these changes:
 * fixed partial call (app/views/steps/add.html.ejs)
 * changed labe attribute "for" from "title" to "toDoId" and added some css classes for a twitter bootstrap (app/views/steps/form.html.ejs)
 * changed css class "span8" to "span12" (app/views/to_dos/index.html.ejs)