knngist - 0.8

http://www.sigaev.ru/misc/builtin_knngist_core-0.8.gz
http://www.sigaev.ru/misc/builtin_knngist_itself-0.8.gz
http://www.sigaev.ru/misc/builtin_knngist_proc-0.8.gz
http://www.sigaev.ru/misc/builtin_knngist_contrib_pg_trgm-0.8.gz
http://www.sigaev.ru/misc/builtin_knngist_contrib_btree_gist-0.8.gz

Changes:
* pg_amop has boolean column amoporder which points to clause's usage of
   operator
* Syntax of CREATE OPERATOR CLASS
      CREATE OPERATOR CLASS ...
          [ORDER] OPERATOR ....
   ORDER OPERATOR is marked with pg_amop.amoporder = true
* Bool-returning operator could not be used as ORDER OPERATOR, but type of
   returning value still should have a default Btree operator class.
* Added flag SK_ORDER to SkanKey flag to indicate order operation, so access
   methods (only GiST right now) should check this flag (in previous versions of
   patch GiST checked returned value of operator's function)

-- 
Teodor Sigaev                                   E-mail: teodor@sigaev.ru
                                                    WWW: http://www.sigaev.ru/