Define wxDEBUG_LEVEL in both debug and release builds as 1.

By default include assertions and debug logging in both debug and release
builds but disable them in application release builds (when NDEBUG is
defined).

Also update (more accurately, replace) debugging overview.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@61886 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/app.h

@@ -1053,3 +1053,37 @@ void wxExit();
 
 //@}
 
+/** @addtogroup group_funcmacro_debug */
+//@{
+
+/**
+    @def wxDISABLE_DEBUG_SUPPORT()
+
+    Use this macro to disable all debugging code in release build when not
+    using IMPLEMENT_APP().
+
+    Currently this macro disables assert checking and debug and trace level
+    logging messages in release build (i.e. when @c NDEBUG is defined). It is
+    used by IMPLEMENT_APP() macro so you only need to use it explicitly if you
+    don't use this macro but initialize wxWidgets directly (e.g. calls
+    wxEntry() or wxEntryStart() itself).
+
+    If you do not want to disable debugging code even in release build of your
+    application, you can use wxSetDefaultAssertHandler() and
+    wxLog::SetLogLevel() with @c wxLOG_Max parameter to enable assertions and
+    debug logging respectively.
+
+    @see wxDISABLE_ASSERTS_IN_RELEASE_BUILD(),
+         wxDISABLE_DEBUG_LOGGING_IN_RELEASE_BUILD(),
+         @ref overview_debugging
+
+    @since 2.9.1
+
+    @header{wx/app.h}
+ */
+#define wxDISABLE_DEBUG_SUPPORT() \
+    wxDISABLE_ASSERTS_IN_RELEASE_BUILD(); \
+    wxDISABLE_DEBUG_LOGGING_IN_RELEASE_BUILD()
+
+//@}
+