FIX: include memory in sitkPixelContainer.h
FIX: include memory in sitkPixelContainer.h

This seems to fix the compilation errors for gcc 4.4.5 Ubuntu

SimpleITK/Staging,SimpleITK/Staging,SimpleITK/Staging,SimpleITK/Staging,SimpleITK/Staging,SimpleITK/Staging,SimpleITK/Staging