Remove double-quoting of table names in clusterdb. BACKWARD COMPABILITY

BREAKAGE.

Remove double-quoting of index/table names in reindexdb.  BACKWARD
COMPABILITY BREAKAGE.

Document thate user/database names are preserved with double-quoting by
command-line tools like vacuumdb.

doc/src/sgml/reference.sgml

@@ -198,6 +198,14 @@
     applications is that they can be run on any host, independent of
     where the database server resides.
    </para>
+
+   <para>
+    When specified on the command line, user and databases names have
+    their case preserved &mdash; the presence of spaces or special
+    characters might require quoting.  Table names and other identifiers
+    do not have their case preserved, except where documented, and
+    might require quoting.
+   </para>
   </partintro>
 
    &clusterdb;