manual.texi 1) earlier change to @xref{} used 2-arg form; change

manual.texi	to 3-arg form so last arg shows up in printed output.
manual.texi	2) mysql.server no longer needs to use su or store the
manual.texi	root password.
manual.texi	3) other misc small changes.


Docs/manual.texi:
  earlier change to @xref{} used 2-arg form; change
  to 3-arg form so last arg shows up in printed output.
  mysql.server no longer needs to use su or store the
  root password.
  other misc small changes