Make wxWS_EX_VALIDATE_RECURSIVELY default (and only) behaviour

In practice, almost everybody using validators also seems to use this style,
so make it the default (this hadn't been done when it was originally
introduced because of compatibility concerns, but now, 15+ years later, it's
probably safe enough to change this).

interface/wx/window.h

@@ -190,11 +190,6 @@ enum wxWindowVariant
     @endStyleTable
 
     @beginExtraStyleTable
-    @style{wxWS_EX_VALIDATE_RECURSIVELY}
-           By default, wxWindow::Validate(), wxWindow::TransferDataTo() and
-           wxWindow::TransferDataFromWindow() only work on
-           direct children of the window (compatible behaviour).
-           Set this flag to make them recursively descend into all subwindows.
     @style{wxWS_EX_BLOCK_EVENTS}
            wxCommandEvents and the objects of the derived classes are
            forwarded to the parent window and so on recursively by default.
@@ -2936,8 +2931,8 @@ public:
         Transfers values from child controls to data areas specified by their
         validators. Returns @false if a transfer failed.
 
-        If the window has @c wxWS_EX_VALIDATE_RECURSIVELY extra style flag set,
-        the method will also call TransferDataFromWindow() of all child windows.
+        Notice that this also calls TransferDataFromWindow() for all children
+        recursively.
 
         @see TransferDataToWindow(), wxValidator, Validate()
     */
@@ -2947,8 +2942,8 @@ public:
         Transfers values to child controls from data areas specified by their
         validators.
 
-        If the window has @c wxWS_EX_VALIDATE_RECURSIVELY extra style flag set,
-        the method will also call TransferDataToWindow() of all child windows.
+        Notice that this also calls TransferDataToWindow() for all children
+        recursively.
 
         @return Returns @false if a transfer failed.
 
@@ -2958,8 +2953,8 @@ public:
 
     /**
         Validates the current values of the child controls using their validators.
-        If the window has @c wxWS_EX_VALIDATE_RECURSIVELY extra style flag set,
-        the method will also call Validate() of all child windows.
+
+        Notice that this also calls Validate() for all children recursively.
 
         @return Returns @false if any of the validations failed.