Merge branch 'Tryibion-deselect-content'

Source/Editor/Windows/ContentWindow.Navigation.cs

@@ -69,7 +69,6 @@ namespace FlaxEditor.Windows
 
                 // Update UI
                 UpdateUI();
-                _view.SelectFirstItem();
             }
         }
 

Source/Editor/Windows/ContentWindow.cs

@@ -941,6 +941,17 @@ namespace FlaxEditor.Windows
                 return true;
             }
 
+            if (button == MouseButton.Left)
+            {
+                // Find control that is under the mouse
+                var c = GetChildAtRecursive(location);
+                if (c is ContentView)
+                {
+                    _view.ClearSelection();
+                    return true;
+                }
+            }
+
             return base.OnMouseUp(location, button);
         }