Remove contrib/tsearch2.

This module was intended to ease migrations of applications that used
the pre-8.3 version of text search to the in-core version introduced
in that release.  However, since all pre-8.3 releases of the database
have been out of support for more than 5 years at this point, we
expect that few people are depending on it at this point.  If some
people still need it, nothing prevents it from being maintained as a
separate extension, outside of core.

Discussion: http://postgr.es/m/CA+Tgmob5R8aDHiFRTQsSJbT1oreKg2FOSBrC=2f4tqEH3dOMAg@mail.gmail.com

Author: robertmhaas

Diff for: .gitattributes

@@ -13,7 +13,6 @@ README.*	conflict-marker-size=32
 
 # Certain data files that contain special whitespace, and other special cases
 *.data						-whitespace
-contrib/tsearch2/sql/tsearch2.sql		whitespace=space-before-tab,blank-at-eof,-blank-at-eol
 contrib/pgcrypto/sql/pgp-armor.sql		whitespace=-blank-at-eol
 doc/bug.template				whitespace=space-before-tab,-blank-at-eof,blank-at-eol
 src/backend/catalog/sql_features.txt		whitespace=space-before-tab,blank-at-eof,-blank-at-eol

Diff for: contrib/Makefile

@@ -47,7 +47,6 @@ SUBDIRS = \
 		test_decoding	\
 		tsm_system_rows \
 		tsm_system_time \
-		tsearch2	\
 		unaccent	\
 		vacuumlo