Fix for server hang bug


mysql-test/r/heap.result:
  Bug#4411
    Test for server hang bug
mysql-test/t/heap.test:
  Bug#4411
    Test for server hang bug
sql/opt_sum.cc:
  Bug#4411
    Allow code to exit the loop.
BitKeeper/etc/logging_ok:
  Logging to logging@openlogging.org accepted