pgsql: Fix upgrade of contrib/btree_gist from 9.0.

Fix upgrade of contrib/btree_gist from 9.0.

The initial version of the update-from-unpackaged script neglected to
include the <> operators that were added to the opclasses during 9.1.
To make this script produce the same final state as the regular install
script, use the same ALTER OPERATOR FAMILY trick as in pg_trgm.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/ec65a79db2a423a156cda8e862d34052d7175a86

Modified Files
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contrib/btree_gist/btree_gist--1.0.sql             |   96 +++++++++++++++-----
contrib/btree_gist/btree_gist--unpackaged--1.0.sql |   68 ++++++++++++++
2 files changed, 141 insertions(+), 23 deletions(-)