iprt/tarvfs: Rewrote the tar parser to deal with header sequences used by solaris, gnu and pax while being offline yesterday. Only GNU long link and long names are supported, but adding pax and solaris support is possible. This also resolves some of the ustar<space><space> vs. ustart<null>00 problems (the latter was not readable previously).

some tar bits

iprt/tarvfs: Working on validating and parsing the tar headers.

iprt/vfs/tar: more code.

iprt: Working on tar vfs.