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

@@ -448,6 +448,9 @@
 #lc_numeric = 'C'			# locale for number formatting
 #lc_time = 'C'				# locale for time formatting
 
+# default configuration for text search
+#default_text_search_config = 'pg_catalog.simple'
+
 # - Other Defaults -
 
 #explain_pretty_print = on