Replace most inclusions of MemoryX.h with <memory> ...

... Most often it was needed for a custom definition of std::make_unique, but
we build C++14 now.

src/toolbars/ToolDock.h

@@ -17,6 +17,7 @@
 #include <wx/defs.h>
 
 #include "ToolBar.h"
+#include "../MemoryX.h"
 
 class wxCommandEvent;
 class wxEraseEvent;