Using a @vtable provides a context for processing @items
	whereby it can be known the @items should have header and
	standards annotations.  This commit converts @tables of such
	@items to @vtables in order to establish a framework for
	automated processing.

	A pleasant consequence of these changes are that @items
	previously absent from the Variable and Constant Macro Index
	are present now.  Any @vindex entries are removed, being
	unnecessary, as they are automatically indexed due to being in
	a @vtable.  Note that @vindex entries previously detected by
	summary.awk will still be detected as @items with appropriate
	annotations.

	The @table of the NSS databases are converted to a @table
	because 1) those @items are not variables (and will no longer
	appear in the Variable and Constant Macro Index) and 2) they
	do not need header and standards annotations, so the incorrect
	context is fixed.

	* manual/arith.texi: Convert @tables of variables to @vtables.
	* manual/filesys.texi: Likewise.
	* manual/llio.texi: Likewise.
	* manual/memory.texi: Likewise.
	* manual/process.texi: Likewise.
	* manual/resource.texi: Likewise.
	* manual/search.texi: Likewise.
	* manual/signal.texi: Likewise.
	* manual/socket.texi: Likewise.
	* manual/stdio.texi: Likewise.
	* manual/sysinfo.texi: Likewise.
	* manual/syslog.texi: Likewise.
	* manual/terminal.texi: Likewise.
	* manual/time.texi: Likewise.
	* manual/users.texi: Likewise.
	* manual/nss.texi: Convert an incorrect @vtable to a @table.
---
 manual/arith.texi    |  8 ++------
 manual/filesys.texi  | 39 ++++++---------------------------------
 manual/llio.texi     | 34 ++++++++++++++--------------------
 manual/memory.texi   |  8 ++++----
 manual/nss.texi      |  4 ++--
 manual/process.texi  |  8 ++++----
 manual/resource.texi | 26 ++++++++------------------
 manual/search.texi   |  4 ++--
 manual/signal.texi   | 21 ++++-----------------
 manual/socket.texi   | 17 ++++-------------
 manual/stdio.texi    |  7 ++-----
 manual/sysinfo.texi  |  8 ++++----
 manual/syslog.texi   |  4 ++--
 manual/terminal.texi | 23 ++++++-----------------
 manual/time.texi     |  4 ++--
 manual/users.texi    | 27 ++++-----------------------
 16 files changed, 70 insertions(+), 172 deletions(-)