pgsql: Extend r-tree operator classes to handle Y-direction tests

Log Message:
-----------
Extend r-tree operator classes to handle Y-direction tests equivalent
to the existing X-direction tests. An rtree class now includes 4 actual
2-D tests, 4 1-D X-direction tests, and 4 1-D Y-direction tests.
This involved adding four new Y-direction test operators for each of
box and polygon; I followed the PostGIS project's lead as to the names
of these operators.
NON BACKWARDS COMPATIBLE CHANGE: the poly_overleft (&<) and poly_overright
(&>) operators now have semantics comparable to box_overleft and box_overright.
This is necessary to make r-tree indexes work correctly on polygons.
Also, I changed circle_left and circle_right to agree with box_left and
box_right --- formerly they allowed the boundaries to touch. This isn't
actually essential given the lack of any r-tree opclass for circles, but
it seems best to sync all the definitions while we are at it.

Modified Files:
--------------
pgsql/contrib/rtree_gist:
rtree_gist.c (r1.13 -> r1.14)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/rtree_gist/rtree_gist.c.diff?r1=1.13&r2=1.14)
rtree_gist.sql.in (r1.10 -> r1.11)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/rtree_gist/rtree_gist.sql.in.diff?r1=1.10&r2=1.11)
pgsql/doc/src/sgml:
func.sgml (r1.258 -> r1.259)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/func.sgml.diff?r1=1.258&r2=1.259)
indices.sgml (r1.50 -> r1.51)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/indices.sgml.diff?r1=1.50&r2=1.51)
xindex.sgml (r1.39 -> r1.40)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/xindex.sgml.diff?r1=1.39&r2=1.40)
pgsql/src/backend/access/rtree:
rtstrat.c (r1.26 -> r1.27)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/rtree/rtstrat.c.diff?r1=1.26&r2=1.27)
pgsql/src/backend/utils/adt:
geo_ops.c (r1.88 -> r1.89)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/geo_ops.c.diff?r1=1.88&r2=1.89)
pgsql/src/include/access:
rtree.h (r1.40 -> r1.41)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/access/rtree.h.diff?r1=1.40&r2=1.41)
pgsql/src/include/catalog:
catversion.h (r1.280 -> r1.281)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/catversion.h.diff?r1=1.280&r2=1.281)
pg_am.h (r1.35 -> r1.36)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_am.h.diff?r1=1.35&r2=1.36)
pg_amop.h (r1.63 -> r1.64)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_amop.h.diff?r1=1.63&r2=1.64)
pg_operator.h (r1.133 -> r1.134)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_operator.h.diff?r1=1.133&r2=1.134)
pg_proc.h (r1.369 -> r1.370)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_proc.h.diff?r1=1.369&r2=1.370)
pgsql/src/include/utils:
geo_decls.h (r1.46 -> r1.47)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/geo_decls.h.diff?r1=1.46&r2=1.47)
pgsql/src/test/regress/expected:
opr_sanity.out (r1.58 -> r1.59)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/opr_sanity.out.diff?r1=1.58&r2=1.59)
polygon.out (r1.11 -> r1.12)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/polygon.out.diff?r1=1.11&r2=1.12)
pgsql/src/test/regress/sql:
polygon.sql (r1.7 -> r1.8)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/sql/polygon.sql.diff?r1=1.7&r2=1.8)