mysqldump skips information_schema db
'use' now can use information_schema db
changed value of column 'Null' to 'NO' if column is not nullable


client/mysqldump.c:
  mysqldump skips information_schema db
mysql-test/r/alter_table.result:
  changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/create.result:
  changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/ctype_collate.result:
  changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/ctype_recoding.result:
  changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/ctype_ujis.result:
  changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/drop.result:
  changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/func_sapdb.result:
  changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/func_time.result:
  changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/gis.result:
  changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/information_schema.result:
  Added couple of tests
mysql-test/r/information_schema_inno.result:
  Removed coulmn 'CONTRAINT_METOD' from TABLE_CONSTRAINTS
  Added column 'POSITION_IN_UNIQUE_CONSTRAINT' to KEY_COLUMN_USAGE
mysql-test/r/innodb.result:
  changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/ndb_autodiscover.result:
  changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/ps_1general.result:
  changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/rpl000009.result:
  changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/rpl_create_database.result:
  changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/schema.result:
  changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/select.result:
  changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/show_check.result:
  changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/sp.result:
  changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/type_enum.result:
  changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/type_ranges.result:
  changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/t/information_schema.test:
  Added couple of tests
sql/sql_acl.cc:
  Don't display 'usage' privilege in TABLE_PRIVILEGES if we have columns privileges
sql/sql_db.cc:
  'use' now can use information_schema db
sql/sql_show.cc:
  code cleanup
  informaton_schema(IS) db now contains data about IS itself
sql/sql_yacc.yy:
  A fix(wrong behavour of 'SHOW COLUMNS, SHOW KEYS' with 'where condition')