Update for better documentation

* Describe **how to use local git repository** in `README`. It's good for development.
* Edit content as title and subtitle.
* Add actual link for Affogato Scala API Doc which published in `docs.mintpresso.com`.
* Update README about `sbt console` use.
* Update README about play framework 2 configuration.
* Correct misspell.

```scala
scala> affogato.set(Map[String, String]('user -> "admire93@gmail.com", 'name -> "kanghyojun"))
Option[Point] = Some(Point(...))
```

should be `Map[Symbol, String]`.