/usr/include.
Make comment about mp.h missing and remove it from the list of files.
Fix installation of ufs include files as this is now a tree ufs/{ffs,lfs,
mfs,ufs}.
Make setting of SHARED optional by makeing it SHARED?=.
Comment out installation of X11 includes since it does not work
for XFree86 until we get XFree86 to install as /usr/X11.
Update _PATH_UNIX to be /kernel. Remove /usr/{contrib,old}/bin from
_PATH_STDPATH.
