Tsearch2 functionality migrates to core. The bulk of this work is by

Oleg Bartunov and Teodor Sigaev, but I did a lot of editorializing,
so anything that's broken is probably my fault.

Documentation is nonexistent as yet, but let's land the patch so we can
get some portability testing done.

src/test/regress/sql/create_table.sql

@@ -231,3 +231,9 @@ CREATE TABLE array_index_op_test (
 	i			int4[],
 	t			text[]
 );
+
+CREATE TABLE test_tsvector( 
+	t text, 
+	a tsvector 
+);
+