Remove the unnecessary inclusion of disklabel.h in cd9660_vfsops.c so
that I don't have to worry about the latter when changing disklabel.h.
Supply prototypes for some functions that were implicitly declared and
fix the resulting warnings and errors (timevals were punned to timespecs).
device block which was stopping symbolic links working.
cd9660_readdir was incorrectly casting a pointer to the d_namlen field of a
struct dirent to a (u_short*) which caused the directory entries "." and ".."
to read incorrectly.
Submitted by: dfr
