scripts/fill_help_tables.sh:
  percent_xxx variables added to avoid /0 error.
scripts/mysql_install_db.sh:
  A fix (bug #5823: mysql_install_db fails due to incorrect max_allowed_packet).          
  --net_buffer_length=16K added.
sql/net_serv.cc:
  Typo fixed.
sql/sql_parse.cc:
  A fix (bug #5823: mysql_install_db fails due to incorrect max_allowed_packet).
  Auto extend net buffer in bootstrap mode.