Because c++14 zomg woot woot

Index: src/screen.cxx
--- src/screen.cxx.orig
+++ src/screen.cxx
@@ -27,8 +27,8 @@ ScreenManager::MakePage(const PageMeta &sf) noexcept
 		return i;
 
 	auto j = pages.emplace(&sf,
-			       sf.init(*this, main_window.w,
-				       main_window.size));
+			       std::unique_ptr<Page>(sf.init(*this, main_window.w,
+				       main_window.size)));
 	assert(j.second);
 	return j.first;
 }