Fix for the typelib auto-update feature

Hi James,

This fix makes HexEdit to automatically pick up changes in the typelib files. Obviously this feature was planned for and mostly implemented, I just completed the code.

You probably don't want to pull 3d9391b. It changes the `HexEdit.rc` to remove the unnecessary MFC dependency. But since this file is auto-generated you'll lose these changes anyway as soon as you edit it using the VS tools.