pgsql: Adjust the names of a couple of tsearch index support functions

Log Message:
-----------
Adjust the names of a couple of tsearch index support functions that had
inappropriately generic-sounding names. This is more or less free since
we already forced initdb for the next beta, and it may prevent confusion or
name conflicts (particularly at the C-global-symbol level) down the road.
Per my proposal yesterday.

Modified Files:
--------------
pgsql/contrib/tsearch2:
tsearch2.sql.in (r1.3 -> r1.4)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/tsearch2/tsearch2.sql.in?r1=1.3&r2=1.4)
pgsql/src/backend/utils/adt:
tsginidx.c (r1.7 -> r1.8)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/tsginidx.c?r1=1.7&r2=1.8)
pgsql/src/include/catalog:
catversion.h (r1.439 -> r1.440)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/catversion.h?r1=1.439&r2=1.440)
pg_proc.h (r1.480 -> r1.481)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_proc.h?r1=1.480&r2=1.481)
pgsql/src/include/tsearch:
ts_utils.h (r1.10 -> r1.11)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/tsearch/ts_utils.h?r1=1.10&r2=1.11)