Fixed memory leak when replication restarts in debug mode


include/my_sys.h:
  Added option to not overwrite files to my_copy()
mysql-test/mysql-test-run.sh:
  Fixed --ddd option
  Fixed that mysqld is restarted if there is a testname-master.sh file
mysql-test/r/backup.result:
  Update for security fix in BACKUP TABLE
mysql-test/t/backup.test:
  Update for security fix in BACKUP TABLE
mysys/my_copy.c:
  Added option to not overwrite files to my_copy()
sql/ha_myisam.cc:
  Don't allow BACKUP TABLE to overwrite files
sql/slave.cc:
  Fixed problem with --debug output from 'handle_slave'
  Fixed memory leak when replication restarts in debug mode