AUI panels have captions but no close buttons

In theory there is no reason why the panels cannot be closeable, but for now
this functionality is disabled since there is no way to show the closed panels
again.

radiant/ui/mainframe/AuiLayout.cpp

@@ -22,6 +22,13 @@ namespace ui
 namespace
 {
     const std::string RKEY_ROOT = "user/ui/mainFrame/aui";
+
+    // Return a pane info with default options
+    wxAuiPaneInfo DEFAULT_PANE_INFO(const std::string& caption)
+    {
+        return wxAuiPaneInfo().Caption(caption).Floatable().Dockable().Dock()
+                              .CloseButton(false);
+    }
 }
 
 AuiLayout::AuiLayout()
@@ -79,9 +86,12 @@ void AuiLayout::activate()
 
     // Add the camera and notebook to the left, as with the Embedded layout, and
     // the 2D view on the right
-    _auiMgr.AddPane(_camWnd->getMainWidget(), wxAuiPaneInfo().Left().Dockable().Dock());
-    _auiMgr.AddPane(notebookPanel, wxAuiPaneInfo().Left().Dockable().Dock());
-    _auiMgr.AddPane(xywnd->getGLWidget(), wxAuiPaneInfo().Right().Dockable().Dock());
+    _auiMgr.AddPane(_camWnd->getMainWidget(),
+                    DEFAULT_PANE_INFO(_("Camera")).Left());
+    _auiMgr.AddPane(notebookPanel,
+                    DEFAULT_PANE_INFO(_("Properties")).Left());
+    _auiMgr.AddPane(xywnd->getGLWidget(),
+                    DEFAULT_PANE_INFO(_("2D View")).Right());
     _auiMgr.Update();
 
     topLevelParent->Layout();