functionality into the test case "strict".

The additional sub test cases are part of the SoW6 test draft
(sow6-dates.test) written by Trudy/PeterG. 

sow6-dates will be no longer needed, because "strict" contains with
this extension all sub test cases of sow6-dates.


mysql-test/r/strict.result:
  Updated results
mysql-test/t/strict.test:
  Additional tests