pgpass comment suggestion

There was a discussion months ago about helping people document the
pgpass columns, so I added a documentation sentence suggestion the use
of a comment.  Patch attached and applied to 9.1 and head.

--
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + It's impossible for everything to be true. +
diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
new file mode 100644
index 268b642..d642ede
*** a/doc/src/sgml/libpq.sgml
--- b/doc/src/sgml/libpq.sgml
*************** myEventProc(PGEventId evtId, void *evtIn
*** 6494,6499 ****
--- 6494,6501 ----
  <synopsis>

<replaceable>hostname</replaceable>:<replaceable>port</replaceable>:<replaceable>database</replaceable>:<replaceable>username</replaceable>:<replaceable>password</replaceable>
  </synopsis>
+    (You can add a reminder comment to the file by copying the line above and
+    preceeding it with <literal>#</>.)
     Each of the first four fields can be a literal value, or
     <literal>*</literal>, which matches anything.  The password field from
     the first line that matches the current connection parameters will be