Making the use of BaseViewModel optional

Providing BaseViewModel.From(x) static methods to adapt properties from various context objects
Adds DevTools\HomeController actions to verify results
AdaptedViewModel exposes public properties or view data dictionary entries as appropriate
Layout view engine restriction loosened to allow any ViewResult to be themed (not Partial of course)

--HG--
branch : dev

src/Orchard.Web/Modules/Orchard.DevTools/Views/Home/Simple.aspx

@@ -0,0 +1,10 @@
+<%@ Page Language="C#" Inherits="Orchard.Mvc.ViewPage<Simple>" %>
+
+<%@ Import Namespace="Orchard.DevTools.Models" %>
+<h1>
+    <%= H(Model.Title) %></h1>
+<p>
+    Quantity:
+    <%= Model.Quantity %></p>
+<div style="border: solid 1px #ccc;">
+    <% Html.RenderAction("_RenderableAction"); %></div>