fixed null processing in NOT operation used in ALL subquery (Bug #6247)


mysql-test/r/subselect.result:
  new tests of ALL/ANY wiews
mysql-test/t/subselect.test:
  new tests of ALL/ANY wiews
sql/item_cmpfunc.cc:
  fixed special NOT ALL processing
  fixed processing max/min optimized subqueries with empty results (added methods to detect empty results) and special NOP operation to process them for SOME/ANY sobqueries
sql/item_cmpfunc.h:
  fixed processing max/min optimized subqueries with empty results (added methods to detect empty results) and special NOP operation to process them for SOME/ANY sobqueries
sql/item_subselect.cc:
  reporting empty result added for max/min subqueries
sql/item_subselect.h:
  reporting empty result added for max/min subqueries
sql/item_sum.cc:
  reporting empty result added fox max/min aggregate functions
sql/item_sum.h:
  reporting empty result added fox max/min aggregate functions
sql/sql_class.cc:
  reporting empty result added for max/min subqueries
sql/sql_parse.cc:
  reporting empty result added for max/min subqueries
sql/sql_union.cc:
  reporting empty result added for max/min subqueries