Remove the default_do_language parameter, instead making DO use a hardwired

default of "plpgsql".  This is more reasonable than it was when the DO patch
was written, because we have since decided that plpgsql should be installed
by default.  Per discussion, having a parameter for this doesn't seem useful
enough to justify the risk of application breakage if the value is changed
unexpectedly.

src/backend/utils/misc/guc.c

@@ -10,7 +10,7 @@
  * Written by Peter Eisentraut <peter_e@gmx.net>.
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.535 2010/01/24 21:49:17 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.536 2010/01/26 16:33:40 tgl Exp $
  *
  *--------------------------------------------------------------------
  */
@@ -383,8 +383,6 @@ char	   *external_pid_file;
 
 char	   *pgstat_temp_directory;
 
-char	   *default_do_language;
-
 char	   *application_name;
 
 int			tcp_keepalives_idle;
@@ -2603,15 +2601,6 @@ static struct config_string ConfigureNamesString[] =
 	},
 #endif   /* USE_SSL */
 
-	{
-		{"default_do_language", PGC_USERSET, CLIENT_CONN_STATEMENT,
-			gettext_noop("Sets the language used in DO statement if LANGUAGE is not specified."),
-			NULL
-		},
-		&default_do_language,
-		"plpgsql", NULL, NULL
-	},
-
 	{
 		{"application_name", PGC_USERSET, LOGGING,
 		 gettext_noop("Sets the application name to be reported in statistics and logs."),

src/backend/utils/misc/postgresql.conf.sample

@@ -432,7 +432,6 @@
 #temp_tablespaces = ''			# a list of tablespace names, '' uses
 					# only default tablespace
 #check_function_bodies = on
-#default_do_language = 'plpgsql'
 #default_transaction_isolation = 'read committed'
 #default_transaction_read_only = off
 #session_replication_role = 'origin'