Fixed some Windows compiler warnings (change submitted by Dan Wexler).
Fixed some Windows compiler warnings (change submitted by Dan Wexler).

oglops/PyIlmBase,oglops/PyIlmBase,oglops/IlmBase,oglops/OpenEXR,oglops/PyIlmBase,oglops/PyIlmBase,oglops/IlmBase,oglops/IlmBase,oglops/OpenEXR,oglops/OpenEXR