jto/validation — pull request #23 by atamborrino (2014-12-20 22:59:26+00:00)
Title: write xml

Hello,

This PR add Writes to validation-xml.

Example usage:

```scala
val w = To[XmlWriter] { __ => (
(__ \ "firstname").write[String] ~
(__ \ "age").write[Int]
) tupled
}
w.writes("Julien", 28)() mustEqual Julien28

val w1 = To[XmlWriter] { __ => (
attributeW[String]("firstname") ~
attributeW[Int]("age")
) tupled
}
w1.writes("Julien", 28)() mustEqual

val w2 = To[XmlWriter] { __ => (
attributeW[String]("firstname") ~
(__ \ "age").write[Int]
) tupled
}
w2.writes("Julien", 28)() mustEqual 28
```