Various fixes and additional settings for database field storage.  Fixes "not NULL" option and should provide working database field size options for all the types.

CCK always expects there to be a data column defined for a field type, even before field configuration.  Now all computed fields (even non-stored ones) will have a DB column for CCK.  Non-stored computed fields will just not store data in these columns.

Make sure $node is available for custom display code to use in all the formatters that evaluate code.

Removing "Display this field" information from the README.txt.  CCK already controlled field display output, so this option was removed a while back.

#414088 - Rolling back to operating during insert/update rather then presave in order to always have nid available to computed fields.

#339441: 'Display this field' doesn't work. Removed feature since cck in D6 provides 'Display fields'.

#236963 - Intial work to bring HEAD to Drupal 6.x.  First commit is basically my latest patch from this issue with a little string cleanup added.

  data type is text or longtext as per http://drupal.org/node/141340
* Added callbacks to hook_field_settings as per http://drupal.org/node/87619

rather than on view. This makes them available in node.tpl.php.