#14591, User.module links for blocked/non-existant accounts + menu 403/404 issue, patch by Steven and merlinofchaos

  part of the node system!  If you have a module that implements node
  types, you'll have to udpate its CVS HEAD version.

  We replaced _node_name() and _node_types() by _node().  The new _node()
  hook let's you define one or more node types, including their names.
  The implementation of the _node() hook needs to:

   return array($type1 => array('name' => $name1, 'base' => $base1),
                $type2 => array('name' => $name2, 'base' => $base2));

  where $type is the node type, $name is the human readable name of the type
  and $base is used instead of <hook> for <hook>_load, <hook>_view, etc.

  For example, the story module's node hook looks like this:

    function story_node() {
      return array('story' => array('name' => t('story'), 'base' => 'story'));
    }

  The page module's node hook module like:

    function page_node() {
      return array('page' => array('name' => t('page'), 'base' => 'page'));
    }

  However, more complex node modules like the project module and the
  flexinode module can use the 'base' parameter to specify a different base.

  The project module implements two node types, proejcts and issues, so it
  can do:

    function project_node() {
      return array(
       array('project_project' => array('name' => t('project'), 'base' => 'project'),
       array('project_issue' => array('name' => t('issue'), 'base' => 'project_issue'));
    }

  In the flexinode module's case there can only one base ...

  This hook will simplify the CCK, and will make it easy (or easier) to merge
  the story and page module.

  In addition, node_list() became node_get_types().  In addition, we created
  the following functions: node_get_name($type) and node_get_base($type).

  Usernames can now be themed; eg. an icon/avatar could be added.

  TODO: update contributed modules + update the migration docs.

  It did not return nor print its output.

- Patch 20910 by chx: centralize print theme page.

    - permissions menu link updates in a number of modules help
    - anchor link fix in distributed auth help
    - "my account" link fix in user help
    - spelling correction in tracker.module help

- I also changed 'admin/access/perms' to 'admin/access/permissions'.

  Goba: it would be nice if one of the core themes would showcase this functionality. ;-)

- I had to use DISTINCT for the tracker.module's SQL queries.

- Patch #16253 by Goba: this simple and straightforward patch adds the ability to define different types of markers (while retaining the old default behaviour of the new and required markers to look the same). Someone with enough time on his hands might be able to partition the new marker to a real new marker and a changed marker (since node_is_new() returns TRUE even if nodes changed, and not only when they are new). This is the base on which the new patch can be worked though.

- Fix tracker pager count query being wrong (it did not return a count but a set, and it counted nodes with more than 1 comment as multiple nodes).
- Clean up various SQL queries: removing literally inserted data (db_escape_string is evil!), fixing single "%" which should be "%%", fixing integers being compared as strings.

- Tiny code style fix

- Patch #14731 by chx: made it possible to rewrite node queries.

- Patch #14262 by Richard: help text improvements for the tracker module.

- Patch #12783 by Stefan: various small consistency/usability improvements.

- Modifed patch by ccourtne: made the tracker module take advantage of the node_comment_statistics table.  Improves performance of the tracker page by facter 10 because it eliminates up to 20 SQL queries.

- Patch #11577 by drumm: changed t('ago') -> t('%time ago', ...) to make it
  translatable in languages such as Spanish.

- Usability improvement: the 'recent posts' feature on the user pages lead
  to a page with a confusing (wrong) title so I shuffled things around a bit
  and tab-ified it as 'track'.

- Patch #8179 by JonBob: reintroduced menu caching.

- Patch by JonBob: for consistency and readability, add brief descriptions of each source file inside the @file comment block at the head of the file. This helps with Doxygen indexing, and also allows neophytes to see what a file does immediately on opening the source, regardless of the organization of the hooks.

- Code improvements by Stefan: use capital letters for header titles (and added some missing t() functions).

- Patch #9330: ucfirst() gives problem when used with multibyte charset.
  Replaced the use of ucfirst() with a CSS-based solution.

- Patch #9543 by JonBob: added node-level access control!

- Patch #9478 by JonBob: allow printf-style arguments in pager_query.

  Currently pager_query() is the black sheep of the database query family, because it does not allow for printf-style arguments to be inserted in the query. This is a problem because it introduces developer confusion when moving from an unpaged query to a paged one, and it encourages substitution of variables directly into the query, which can bypass our check_query() security feature.

  This patch adds this ability to pager_query(). The change is backwards-compatible, but a couple calls to the function in core have been changed to use the new capability.

- Patch by Matt: made it possible to alias an URL multiple times.