Add wxIntegerValidator and wxFloatingPointValidator classes.

Add validators for integer and floating point numbers.

Add an example of their use to the validate sample as well as a new unit test
and documentation for them.

Use the new classes instead of wxTextValidator in wxGrid code.

Closes #12166.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@66714 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/validate.h

@@ -38,7 +38,8 @@
     @stdobjects
     ::wxDefaultValidator
 
-    @see @ref overview_validator, wxTextValidator, wxGenericValidator
+    @see @ref overview_validator, wxTextValidator, wxGenericValidator,
+        wxIntegerValidator, wxFloatingPointValidator
 */
 class wxValidator : public wxEvtHandler
 {