BOOTLIB -- C callable file primitives used by the bootstrap utilities.

This is a somewhat adhoc interface consisting of a collection of low level
functions required by the bootstrap utilities.  As far as possible these
use the iraf kernel, but occasionally non-kernel facilities are required or
desirable.  The purpose of this interface is to isolate the machine dependence
of the bootstrap utilities from the bulk of the code, making it easier to
maintain IRAF on different hosts, as well as to make it easier to port IRAF
to a new host.  No attempt has been made to specify this interface carefully;
it is not necessary since only a limited number of programs use the routines.

Partial list of functions (grows sporadically):

	char *	     vfn2osfn (vfn, mode)		# Map filenames
	char *	     osfn2vfn (osfn)

	      fd = os_diropen (dir)			# Read directories
		  os_dirclose (fd)
		     os_gfdir (fd, fname, maxch)

	bool	    os_access (fname, mode, type)	# General file
		     os_chdir (dir)
		     os_close (fd)
		       os_cmd (cmd)
		     os_close (fd
		 os_createdir (dirname, mode)
		os_createfile (fname, mode, type)
		    os_delete (fname)
		     os_fcopy (oldfile, newfile)
		 os_fpathname (vfn, pathname, maxch)
	long	     os_fdate (file)
	char *      os_getenv (ennvar)
		 fd = os_open (fname, mode, type)
		  os_setfmode (fname, mode)
		  os_setowner (fname, uid, gid)
		  os_setmtime (fname, mtime)
		   os_sysfile (fname, outstr, maxch)
		      os_read (fd, buf, nbytes)
		     os_write (fd, buf, nbytes)

	       fd = tape_open (fname, mode)		# Tape or disk file
		   tape_close (fd)
		    tape_read (fd, buf, nbytes)
		   tape_write (fd, buf, nbytes)


Tasks which use this library must also use the kernel library (libos.a).
Tasks which use full filename mapping will also need libsys.a and libvops.a,
however the system can be bootstrapped with simpler filename mapping and
then the utilities relinked with full filename mapping, once the system
libraries have been generated.  Note that no VOS level i/o is used (only
kernel level i/o functions are used), hence an IRAF main is not required
to initialize the VOS i/o system.
