[Libguestfs] Patch to build hivex lib on Windows

Hi I'm just posting this here in case someone is interested in building hivex on Windows (mingw32). The attached patch allows building the lib but not the tools (hivexsh etc..) as there are some more problems to solve. In short terms, this patch replaces file i/o functions and mmap(), munmap() with their win32api pendants. cu -- Unix _IS_ user friendly - it's just selective about who its friends are!