Initial wxInfoBar implementation.

Add generic implementation, documentation and examples showing the use of the
new class in the samples.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@62268 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/chkconf.h

@@ -696,6 +696,14 @@
 #   endif
 #endif /* !defined(wxUSE_IMAGLIST) */
 
+#ifndef wxUSE_INFOBAR
+#   ifdef wxABORT_ON_CONFIG_ERROR
+#       error "wxUSE_INFOBAR must be defined."
+#   else
+#       define wxUSE_INFOBAR 0
+#   endif
+#endif /* !defined(wxUSE_INFOBAR) */
+
 #ifndef wxUSE_JOYSTICK
 #   ifdef wxABORT_ON_CONFIG_ERROR
 #       error "wxUSE_JOYSTICK must be defined."