Fixed test suite for HPUX 10.20 and MacOSX


Build-tools/Do-compile:
  Added timeout to mysqladmin shutdown commands
  Kill old running mysqld started by earlier runs
  Removed run time warning from LD_LIBRARY_PATH
client/mysqladmin.c:
  Return 1 if pid file isn't deleted on shutdown.
  Fix error message if pid file is not deleted
client/mysqltest.c:
  Always allow --debug flag
  (Makes it easier to run mysql-test-run)
mysql-test/mysql-test-run.sh:
  A lot of safety fixes. 
  This fixes some problems with test suite for HPUX 10.20 and MacOSX
sql-bench/bench-init.pl.sh:
  Allow tests to change time limit.
sql-bench/crash-me.sh:
  Indentation cleanups
  Added DROP for a created table
sql-bench/test-alter-table.sh:
  Added default time limit
  Changed test to be estimated to get down run time.
  Fixed that add_multi_col is detected
sql-bench/test-insert.sh:
  Comment cleanup
sql/mysql_priv.h:
  Removed not needed prototype.
sql/mysqld.cc:
  Removed DBUG warnings
  Removed default argument for clean_up() and made it static.
  More comments.
  Ignore SIGHUP during shutdown
sql/net_pkg.cc:
  More comments
sql/slave.cc:
  Added DBUG_PRINT messages