pgsql: Create an SP-GiST opclass for inet/cidr.

Create an SP-GiST opclass for inet/cidr.

This seems to offer significantly better search performance than the
existing GiST opclass for inet/cidr, at least on data with a wide mix
of network mask lengths. (That may suggest that the data splitting
heuristics in the GiST opclass could be improved.)

Emre Hasegeli, with mostly-cosmetic adjustments by me

Discussion: <CAE2gYzxtth9qatW_OAqdOjykS0bxq7AYHLuyAQLPgT7H9ZU0Cw(at)mail(dot)gmail(dot)com>

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/77e2906821e2aec3c0807866a84c2934feeac8be

Modified Files
--------------
doc/src/sgml/spgist.sgml | 17 +
src/backend/utils/adt/Makefile | 2 +-
src/backend/utils/adt/network_spgist.c | 708 +++++++++++++++++++++++++++++++
src/include/catalog/catversion.h | 2 +-
src/include/catalog/pg_amop.h | 15 +
src/include/catalog/pg_amproc.h | 5 +
src/include/catalog/pg_opclass.h | 1 +
src/include/catalog/pg_opfamily.h | 1 +
src/include/catalog/pg_proc.h | 12 +
src/include/utils/inet.h | 9 +
src/test/regress/expected/inet.out | 148 +++++++
src/test/regress/expected/opr_sanity.out | 11 +-
src/test/regress/sql/inet.sql | 23 +
13 files changed, 951 insertions(+), 3 deletions(-)