[BusyBox] tar filenames > 100 bytes, prefix field

[Glenn McGrath]

In the untar code from archival/libunarchive/get_header_tar.c i have been
ignoring tar's 155 byte prefix field which if used increases the maximum
posix compatable tar filename length to 255 bytes.

The tar creation code looks like it handle GNU style long filenames which
the unlar code doesnt handle either.

This could potentially cause problems for the dpkg applet as the
/var/lib/dpkg/info/*list file is generated at install time and its entries
will be truncated at 100 bytes.

Ive got a few other things on my plate but ill try and sort something out
in the next 3 or 4 days (unless someone beats me to it).



Glenn