Fixed a memory leak that would occur after using any help button

Originally committed to SVN as r3050.

aegisub/src/frame_main.cpp

@@ -585,6 +585,7 @@ void FrameMain::DeInitContents() {
 	delete AssFile::top;
 	delete EditBox;
 	delete videoBox;
+	HelpButton::ClearPages();
 }
 
 

aegisub/src/help_button.cpp

@@ -125,3 +125,7 @@ void HelpButton::InitStatic() {
 		page[_T("Visual Typesetting")] = _T("Visual_Typesetting");
 	}
 }
+
+void HelpButton::ClearPages() {
+	if (pages) delete pages;
+}

aegisub/src/help_button.h

@@ -57,4 +57,5 @@ public:
 	HelpButton(wxWindow *parent,wxString page=_T(""),wxPoint position=wxDefaultPosition,wxSize size=wxDefaultSize);
 
 	static void OpenPage(const wxString page);
+	static void ClearPages();
 };