added HasValue unit test, removed the default.aspx file from the Web project, it now only exists in the UI project but

the codebehind still exist in the web for backwards compatibility. Updated the logging so that the LogHelper
can now write to a TraceContext specified if debugging which is handy if we want to write to the normal trace.

src/Umbraco.Tests/DynamicDocument/DynamicDocumentTestsBase.cs

@@ -59,6 +59,18 @@ namespace Umbraco.Tests.DynamicDocument
 
 		}
 
+		[Test]
+		public void HasValue()
+		{
+			var asDynamic = GetDynamicNode(1173);
+
+			var hasValue = asDynamic.HasValue("umbracoUrlAlias");
+			var noValue = asDynamic.HasValue("blahblahblah");
+
+			Assert.IsTrue(hasValue);
+			Assert.IsFalse(noValue);
+		}
+
 		[Test]
 		public void Take()
 		{