pgsql: Fix shared tsvector/tsquery input code so that we don't say

Log Message:
-----------
Fix shared tsvector/tsquery input code so that we don't say "syntax error in
tsvector" when we are really parsing a tsquery. Report the bogus input,
too. Make styles of some related error messages more consistent.

Modified Files:
--------------
pgsql/src/backend/utils/adt:
tsquery.c (r1.7 -> r1.8)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/tsquery.c?r1=1.7&r2=1.8)
tsvector.c (r1.4 -> r1.5)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/tsvector.c?r1=1.4&r2=1.5)
tsvector_parser.c (r1.1 -> r1.2)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/tsvector_parser.c?r1=1.1&r2=1.2)
pgsql/src/include/tsearch:
ts_utils.h (r1.5 -> r1.6)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/tsearch/ts_utils.h?r1=1.5&r2=1.6)