Remove the PAX_CTG type. It is checked for, but never set.

ok pedro@
Let's use MIN() from <sys/param.h>; no binary change.

ok pedro@
Remove shallow wrappers for major/minor/makedev; no binary change.

ok pedro@
Add tmpfsrd format stub.
some more wip
Make list/read work.

XXX: hardlinks are handled incorrectly
XXX: file names should contain the full path
Reconstruct the files full path.
snprintf() nit
malloc() -> calloc()
sort includes
add comment (hopefully temporary)
error messages
turn on some warnings for now
silly tmpfsrd_wr()
write header
Add read support for sockets & fifos.
Handle hardlinks in read path.
wip: write support

Not much yet, but produces a correct archive header and fills some
parts of the file headers.
Set type.
Use static splay macros.