Add SignInController.

src/main/scala/app/SignInController.scala

@@ -0,0 +1,21 @@
+package app
+
+import jp.sf.amateras.scalatra.forms._
+
+class SignInController extends ControllerBase {
+  
+  case class SignInForm(email: String, password: String)
+  
+  val form = mapping(
+    "email"    -> trim(label("Email",    text(required))), 
+    "password" -> trim(label("Password", text(required)))
+  )(SignInForm.apply)
+  
+  get("/signin"){
+    html.signin()
+  }
+
+  post("/signin", form){ form =>
+    redirect("/%s".format(context.loginUser))
+  }
+}