Support for running Umbraco from a network drive.

src/Umbraco.Core/IO/IOHelper.cs

@@ -85,9 +85,11 @@ namespace Umbraco.Core.IO
         public static string MapPath(string path, bool useHttpContext)
         {
             // Check if the path is already mapped
-            if (path.Length >= 2 && path[1] == Path.VolumeSeparatorChar)
+            if ((path.Length >= 2 && path[1] == Path.VolumeSeparatorChar)
+                || path.StartsWith(@"\\")) //UNC Paths start with "\\". If the site is running off a network drive mapped paths will look like "\\Whatever\Boo\Bar"
+            {
                 return path;
-
+            }
 			// Check that we even have an HttpContext! otherwise things will fail anyways
 			// http://umbraco.codeplex.com/workitem/30946