Add wxModule::AreInitialized()

This internal function will be useful to check if the modules are
already initialized, i.e. if the library is in the "steady state"
between the end of the initialization and the beginning of the cleanup
phases.

src/common/module.cpp

@@ -25,6 +25,7 @@
 wxIMPLEMENT_ABSTRACT_CLASS(wxModule, wxObject)
 
 wxModuleList wxModule::ms_modules;
+bool wxModule::ms_areInitialized = false;
 
 void wxModule::RegisterModule(wxModule* module)
 {
@@ -178,9 +179,18 @@ bool wxModule::InitializeModules()
     // remember the real initialisation order
     ms_modules = initializedModules;
 
+    ms_areInitialized = true;
+
     return true;
 }
 
+void wxModule::CleanUpModules()
+{
+    DoCleanUpModules(ms_modules);
+
+    ms_areInitialized = false;
+}
+
 // Clean up all currently initialized modules
 void wxModule::DoCleanUpModules(const wxModuleList& modules)
 {