Add support for fixed spacers and labels to wxAuiToolBar XRC handler.

Allow specifying "width" and "proportion" attributes for the "space" elements
and add "label" element support.

Closes #15964.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75920 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

misc/schema/xrc_schema.rnc

@@ -326,6 +326,7 @@ builtinNestedClassesNames =
     | "separator"
     | "break"
     | "space"
+    | "label"
     | "tool"
     | "panewindow"
     | "notebookpage"
@@ -540,11 +541,24 @@ wxAuiToolBar =
         (
             windowNode |
             wxToolBar_tool |
+            wxAuiToolBar_label |
             element object { attribute class { "separator" }, platform } |
-            element object { attribute class { "space" },     platform }
+            element object { attribute class { "space" } &
+                platform &
+                [xrc:p="o"] element width {_, t_integer }* &
+                [xrc:p="o"] element proportion {_, t_integer }*
+            }
         )*
     }
 
+wxAuiToolBar_label =
+    element object {
+        attribute class { "label" } &
+            platform &
+            attribute name { t_identifier }? &
+            [xrc:p="important"] element label {_, t_text }* &
+            [xrc:p="o"]         element width {_, t_integer }*
+        }
 
 wxBannerWindow =
     element object {