ScreenshotCommand uses hooks in AudacityCommand and Effect dialogs...

... so that they don't have a static linkage dependency on it, and that frees
it from dependency cycles, to a high level

src/commands/ScreenshotCommand.h

@@ -78,7 +78,7 @@ public:
       nCaptureWhats
    };
 
-   ScreenshotCommand(){ mbBringToTop=true;mIgnore=NULL;};
+   ScreenshotCommand();
    // ComponentInterface overrides
    ComponentInterfaceSymbol GetSymbol() override {return SCREENSHOT_PLUGIN_SYMBOL;};
    wxString GetDescription() override {return _("Takes screenshots.");};