Fix the write_record function to record auto increment
values in a consistent way.

mysql-test/r/auto_increment.result:
  Updated the test result file with the output of the
  new test case added to verify this bug.
mysql-test/t/auto_increment.test:
  Added a new test case to verify this bug.
sql/sql_insert.cc:
  The algorithm for the write_record function
  in sql_insert.cc is (more emphasis given to
  the parts that deal with the autogenerated values)
  
  1) If a write fails
  
     1.1) save the autogenerated value to avoid 
          thd->insert_id_for_cur_row to become 0.
  
     1.2) <logic to handle INSERT ON DUPLICATE KEY
          UPDATE and REPLACE>
  
  2) record the first successful insert id.
  
  explanation of the failure
  --------------------------
  
  As long as 1.1) was executed 2) worked fine.
  
  1.1) was always executed when REPLACE worked 
       with the last row update optimization, but
       in cases where 1.1) was not executed 2)
       would fail and would result in the autogenerated
       value not being saved.
  
  solution
  --------
  
  repeat a check for thd->insert_id_for_cur_row 
  being zero similar to 1.1) before 2) and ensure
  that the correct value is saved.