Synchronize doc/ copies of src/test/examples/.

This is mostly cosmetic, but it might fix build failures, on some
platform, when copying from the documentation.

Back-patch to 9.3 (all supported versions).

doc/src/sgml/libpq.sgml

@@ -8256,13 +8256,16 @@ testlibpq.o(.text+0xa4): undefined reference to `PQerrorMessage'
 <programlisting>
 <![CDATA[
 /*
+ * src/test/examples/testlibpq.c
+ *
+ *
  * testlibpq.c
  *
  *      Test the C version of libpq, the PostgreSQL frontend library.
  */
 #include <stdio.h>
 #include <stdlib.h>
-#include <libpq-fe.h>
+#include "libpq-fe.h"
 
 static void
 exit_nicely(PGconn *conn)
@@ -8383,6 +8386,9 @@ main(int argc, char **argv)
 <programlisting>
 <![CDATA[
 /*
+ * src/test/examples/testlibpq2.c
+ *
+ *
  * testlibpq2.c
  *      Test of the asynchronous notification interface
  *
@@ -8415,6 +8421,10 @@ main(int argc, char **argv)
 #include <errno.h>
 #include <sys/time.h>
 #include <sys/types.h>
+#ifdef HAVE_SYS_SELECT_H
+#include <sys/select.h>
+#endif
+
 #include "libpq-fe.h"
 
 static void
@@ -8526,6 +8536,9 @@ main(int argc, char **argv)
 <programlisting>
 <![CDATA[
 /*
+ * src/test/examples/testlibpq3.c
+ *
+ *
  * testlibpq3.c
  *      Test out-of-line parameters and binary I/O.
  *

src/test/examples/testlibpq2.sql

@@ -3,4 +3,4 @@ CREATE TABLE TBL1 (i int4);
 CREATE TABLE TBL2 (i int4);
 
 CREATE RULE r1 AS ON INSERT TO TBL1 DO
-(INSERT INTO TBL2 VALUES (new.i); NOTIFY TBL2);
+  (INSERT INTO TBL2 VALUES (new.i); NOTIFY TBL2);