Add Instance Manager tests.


mysql-test/include/im_check_os.inc:
  Currently Instance Manager tests are known to work only on UNIX platform.
  This header file is included in each IM-test in order to skip the test
  on Windows.
mysql-test/r/im_daemon_life_cycle.result:
  Results file for Instance Manager daemon test.
mysql-test/r/im_life_cycle.result:
  Results file for Instance Manager life cycle test.
mysql-test/r/im_options_set.result:
  Results file for Instance Manager SET statement test.
mysql-test/r/im_options_unset.result:
  Results file for Instance Manager UNSET statement test.
mysql-test/r/im_utils.result:
  Results file for Instance Manager utils test.
mysql-test/t/im_daemon_life_cycle-im.opt:
  Options file for Instance Manager daemon test.
mysql-test/t/im_daemon_life_cycle.imtest:
  Instance Manager daemon test (mysqltestrun-part).
mysql-test/t/im_life_cycle.imtest:
  Instance Manager life cycle test.
mysql-test/t/im_options_set.imtest:
  Instance Manager SET statement test.
mysql-test/t/im_options_unset.imtest:
  Instance Manager UNSET statement test.
mysql-test/t/im_utils.imtest:
  Instance Manager utils test.
mysql-test/t/kill_n_check.sh:
  The helper script. Its main idea is to kill some process and
  check that the process will (or will not) be restarted.