doc: in contrib-spi, mention and link to the meaning of SPI
authorBruce Momjian <bruce@momjian.us>
Wed, 31 Jan 2018 21:54:33 +0000 (16:54 -0500)
committerBruce Momjian <bruce@momjian.us>
Wed, 31 Jan 2018 21:54:33 +0000 (16:54 -0500)
commit19eb7f84e75f592c7a7134d2d02105a3d44ff7e7
tree06c628297a0b85ad7abb5da8489e442d4d051771
parenta9fd6c321672c14940461ee47c52434bcf2ecdf9
doc:  in contrib-spi, mention and link to the meaning of SPI

Also remove outdated comment about SPI subtransactions.

Reported-by: gregory@arenius.com
Discussion: https://postgr.es/m/151726276676.1240.10501743959198501067@wrigleys.postgresql.org

Backpatch-through: 9.3
doc/src/sgml/contrib-spi.sgml
doc/src/sgml/spi.sgml