Removed wrong warnings in test suite (This was because select_insert / select_create results was not freed.
Added thd to openfrm() for initialization of TABLE->in_use. This fixed a bug in BDB handling where table->in_use was used early


mysql-test/r/key.result:
  Added new tests that shows a bug in warnings hat
mysql-test/t/key.test:
  Added new tests that shows a bug in warnings hat
sql/handler.cc:
  Added thd to openfrm() for initialization of TABLE->in_use
sql/item.cc:
  New function to avoid warnings when giving field a value
sql/item.h:
  New function to avoid warnings when giving field a value
sql/mysql_priv.h:
  Added thd to openfrm() for initialization of TABLE->in_use
sql/opt_range.cc:
  Don't give warnings in optimizer when internally storing a field value in a field. (Should be ok as we ar checking the feild in the WHERE clause later)
sql/sql_base.cc:
  Give memroot explicitely to open_unireg_entry() and open_table() (Makes code simpler)
  Ensure that table->in_use is set early
  New arguments for openfrm()
sql/sql_insert.cc:
  More debugging & comments
sql/sql_parse.cc:
  Delete results for select_insert and select_create. This fixed a bug that generated warnings in test suite
sql/sql_select.h:
  Don't give warnings in optimizer when internally storing a field value in a field. (Should be ok as we ar checking the feild in the WHERE clause later)
sql/sql_table.cc:
  New arguments to open_table() and openfrm()
sql/table.cc:
  Added thd to openfrm() for initialization of TABLE->in_use
  This fixes some bugs in BDB where table->in_use was used