Adding custom Capture helpers in base views

Usage:
@using(Capture(html => Layout.Content.Add(x))) {
  <div>foo</div>
}

And

@using(Capture(Layout.Content)) {
  <div>foo</div>
}

--HG--
branch : 1.x

src/Orchard/Mvc/ViewEngines/Razor/WebViewPage.cs

@@ -175,6 +175,10 @@ namespace Orchard.Mvc.ViewEngines.Razor {
             return new CaptureScope(this, callback);
         }
 
+        public IDisposable Capture(dynamic zone, string position = null) {
+            return new CaptureScope(this, html => zone.Add(html, position));
+        }
+
         class CaptureScope : IDisposable {
             readonly WebPageBase _viewPage;
             readonly Action<IHtmlString> _callback;

src/Orchard/Mvc/ViewPage.cs

@@ -121,6 +121,10 @@ namespace Orchard.Mvc {
             return new CaptureScope(Writer, callback);
         }
 
+        public IDisposable Capture(dynamic zone, string position = null) {
+            return new CaptureScope(Writer, html => zone.Add(html, position));
+        }
+
         public class CaptureScope : IDisposable {
             private readonly HtmlTextWriter _context;
             private readonly Action<IHtmlString> _callback;