Fix some crashes during theme (re)loading

Change-Id: I01405fbe86a48ae79f2cbe633b89f2dcfb1ef266
Signed-off-by: Vojtech Bocek <vbocek@gmail.com>
diff --git a/gui/pages.hpp b/gui/pages.hpp
index 2ce3e13..b042c0d 100644
--- a/gui/pages.hpp
+++ b/gui/pages.hpp
@@ -111,6 +111,7 @@
 	std::vector<xml_node<>*> templates;
 	Page* mCurrentPage;
 	Page* mOverlayPage; // This is a special case, used for "locking" the screen
+	std::vector<xml_document<>*> mIncludedDocs;
 };
 
 class PageManager