- Add 'fwrite' and 'fseek' words for writing to and seeking on files.

- Add 'fwrite' and 'fseek' words for writing to and seeking on files.
- Change the 'fopen' keyword to accept a mode parameter.  Note that this
  will break existing 4th scripts that use fopen.  Thus, the loader
  version has been bumped and loader.4th has been changed to check for a
  sufficient version on i386 and alpha.  Be sure that you either do a full
  world build or install or full build and install of sys/boot after this
  since loader.old won't work with the new 4th files and vice versa.

PR:		kern/32389
Submitted by:	Jonathan Mini <mini@haikugeek.com>
Sponsored by:	ClickArray, Inc.