Small change to hook_help in preparation for D6.

Color coded several "missing," "enabled," "disabled" flags.
Changed CSS to be more like standard format. Added centering of "th" tags.
#185724 - changed logic to include orphan blocks in list.
#185724 - added check for index on blocks table.
#185724 - added delete for blocks_roles that was needed.
#185724 - added associated block check to boxes code, also "warn" and "delete".