CarvFS zero-storage carving filesystem and sleuthkit patches

The CarvFS filesystem is a pseudo filesystem used to
represent carved fragments in image files (currently ewf files and still limmited support for raw dd files) as zero-storage files. This first carvfs release also contains a patch to the sleuthkit that holds carvpath versions of mmls,dls and icat, so using these tools in a zero-storage way becomes possible. The upcomming version of OCFA will include an updated sleuthkit wrapper module that uses these tools in order to greatly limit ocfa storage requirements.