Put comments on the installable procedural languages.

Per suggestion from Josh Kupershmidt.

src/pl/plperl/plperl--1.0.sql

@@ -7,3 +7,5 @@
  */
 
 CREATE PROCEDURAL LANGUAGE plperl;
+
+COMMENT ON PROCEDURAL LANGUAGE plperl IS 'PL/Perl procedural language';

src/pl/plperl/plperlu--1.0.sql

@@ -7,3 +7,5 @@
  */
 
 CREATE PROCEDURAL LANGUAGE plperlu;
+
+COMMENT ON PROCEDURAL LANGUAGE plperlu IS 'PL/PerlU untrusted procedural language';

src/pl/plpgsql/src/plpgsql--1.0.sql

@@ -7,3 +7,5 @@
  */
 
 CREATE PROCEDURAL LANGUAGE plpgsql;
+
+COMMENT ON PROCEDURAL LANGUAGE plpgsql IS 'PL/pgSQL procedural language';

src/pl/plpython/plpython2u--1.0.sql

@@ -7,3 +7,5 @@
  */
 
 CREATE PROCEDURAL LANGUAGE plpython2u;
+
+COMMENT ON PROCEDURAL LANGUAGE plpython2u IS 'PL/Python2U untrusted procedural language';

src/pl/plpython/plpython3u--1.0.sql

@@ -7,3 +7,5 @@
  */
 
 CREATE PROCEDURAL LANGUAGE plpython3u;
+
+COMMENT ON PROCEDURAL LANGUAGE plpython3u IS 'PL/Python3U untrusted procedural language';

src/pl/plpython/plpythonu--1.0.sql

@@ -7,3 +7,5 @@
  */
 
 CREATE PROCEDURAL LANGUAGE plpythonu;
+
+COMMENT ON PROCEDURAL LANGUAGE plpythonu IS 'PL/PythonU untrusted procedural language';

src/pl/tcl/pltcl--1.0.sql

@@ -7,3 +7,5 @@
  */
 
 CREATE PROCEDURAL LANGUAGE pltcl;
+
+COMMENT ON PROCEDURAL LANGUAGE pltcl IS 'PL/Tcl procedural language';

src/pl/tcl/pltclu--1.0.sql

@@ -7,3 +7,5 @@
  */
 
 CREATE PROCEDURAL LANGUAGE pltclu;
+
+COMMENT ON PROCEDURAL LANGUAGE pltclu IS 'PL/TclU untrusted procedural language';