Fix crash when viewing project page

Author: georgeduckett

TeamCoding.Shared/Documents/DocumentPaths.cs

@@ -39,6 +39,10 @@ public static string GetCorrectCase(string fileOrFolder)
         }
         private static string GetCorrectCaseInternal(string fileOrFolder)
         { // http://stackoverflow.com/a/29751774
+            if (string.IsNullOrEmpty(fileOrFolder))
+            {
+                return fileOrFolder;
+            }
             string myParentFolder = Path.GetDirectoryName(fileOrFolder);
             string myChildName = Path.GetFileName(fileOrFolder);
             if (ReferenceEquals(myParentFolder, null))