upload_manifest.py: Specify file type

Specify file type in the cpio header.  This is needed to make cpiod.so
more robust by explicitly checking file type.

Reviewed-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
cpio: File type checking

Make cpiod.so more robust by checking the file type explicitly.

Reviewed-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
cpio: Symbolic link support

Add symbolic link support to cpiod.so parser.  As OSv does not yet
support symlinks, the files are never created on the filesystem.

This is needed for streaming rpm2cpio to OSv guest.

Reviewed-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
cpio: Directory support

Add support for directories.

Found by streaming openjdk rpm2cpio output to OSv.

Reviewed-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>