#228979 - followup : more complete fix for 'don't show empty 'Related content' section on user profiles

Also, fix the query to rely only on current revisions of the node, and run it through db_rewrite_sql

The many_to_one operator looks like it makes more sense to use as the default filter for fields with allowed values lists.

Re-name fields to use Views 1 naming like field_text_value instead of field_text to make updates easier, and alter content.views_convert.inc to match.

Add default filters for all fields, and update fields to switch from string or numeric filters to 'in' operators if there are lists of allowed values.

Add helper function to return Views table name to make it easier to change the tablename in the future, like if we find a way to avoid the need to alias each field as its own table.

#235247, #235224, #224614, fix validation problems with optionwidgets, nodereference, and userreference. This fix gets the forms working correctly and options are saved as they should be. The default value selector in field settings is still broken with this fix, but the node forms now work correctly.

- formatters == theme functions
- allow formatters to handle multiple values

#205997 Fix handling of multiple values in optionwidgets, nodereference, and userreference. Need to have content module *not* set the delta when the widget is handling multiple values so we can transpose arrays for multiple values without interference.

- rename content_install_types() to content_types_install()
- add missing include in content_storage_type() - was OK
  since the function is always called from content_crud.inc
  currently...
- remove unnecessary (array) casts

#196575 userreference autocomplete does not filter by role, need custom autocomplete instead of standard user autocomplete.

#131260 add method so userreference can filter by active/blocked status.

More tweaking of nodereference and userreference to get the right values saved for both selects and autocompletes.

We now let the content module decide how to handle empty values, just go ahead and set the uid or nid, even if empty, then defer to the content module to handle the empty results.

Fix problems with autocomplete handling. It was doubled up in nodereference and a function was missing in userreference. Do the handling in the value callback instead of #process so we don't force a value in if none was selected.

Switch a cleaner method of unnesting the nested elements created by userreference and nodereference.

Added new fuctions to create 'default' field and widget arrays. Available to help expose field structure to external modules. Supplied values are now merged with default values to be sure all parts of the field and widget have indexes set. This means all field values will always return true to isset() and will not create undefined index errors. This also means module authors should not use isset() to test if values exist for form elements. Instead use is_array(), is_numeric() or similar tests.

UI improvements for the screen to select fields and widgets, add a field description to hook_field_info(), then display it to make it easier for the user to make a choice.

Make sure content_storage() has all $columns attributes, not just the names. Rework userreference and nodereference so they can become reusable elements. More updating of documentation.

Had to switch to a different method of identifying the field name. Using #parents wouldn't work in the the default value form, so now setting #field_name as an explicit $element value.

Make sure schema gets refreshed when field types change! More changes to remove use of #field in elements and replace it with new #field_info value in $form; Move install, uninstall, enable, and disable hooks all into .install file; Start developer upgrade documentation.

Add content_notify() function modules can use to let content module take action when they are uninstalled or disabled. Change all field columns to 'not null' = FALSE so we can search for empty values consistently across field types.