Shell Image Viewer crashes the explorer under Windows

As mentioned by thfabba in CORE-7740, shimgvw.dll from ReactOS crashes the Explorer under Windows
(I get it when replacing the Windows one with the one from ReactOS and change to a folder that contains pictures).

The attatched patch replaces the autogenerated stubs for DllRegisterServer(), DllUnregisterServer(), DllGetClassObject() and DllCanUnloadNow() and instead gives them a normal implementation in the Image Viewer's source code. They are still do nothing besides return a appropriate value, but this should hopefully get rid of the explorer crash.