added test/sanity check for master_pos_wait()


mysql-test/r/rpl000016.result:
  do show slave status to test master_pos_wait()
mysql-test/t/rpl000001.test:
  no sleep
mysql-test/t/rpl000002.test:
  no sleep
mysql-test/t/rpl000003.test:
  no sleep
mysql-test/t/rpl000007.test:
  !sleep
mysql-test/t/rpl000008.test:
  !sleep
mysql-test/t/rpl000009.test:
  no sleep
mysql-test/t/rpl000010.test:
  no sleep
mysql-test/t/rpl000011.test:
  no sleep
mysql-test/t/rpl000012.test:
  no sleep
mysql-test/t/rpl000013.test:
  no sleep
mysql-test/t/rpl000014.test:
  no sleep
mysql-test/t/rpl000015.test:
  no sleep
mysql-test/t/rpl000016.test:
  no sleep, test that master_pos_wait() works right
sql/slave.cc:
  fixed bug in master_pos_wait()