- Patch #25522 by Cvbge: _db_query() does not return FALSE in case of errors, as stated in documentation.

- Patch #27863 by Robrecht: fixed order of parameters passed to imagecopy().  Could result in black images.

- Patch #24157 by chx/Robin/...: changed file_exists() to is_file() to fix several problems with modules using theimage toolkit.

- Patch #25143 by Robin: use count() instead of is_array() so we don't render code for empty arrays, and such you don't get warnings using PHP5.

- Patch #24141: fix XML UTF-8 bom issue with PHP5.
    Workaround for the fact that PHP5 cannot parse UTF-8 encoded XML feeds
    that start with the so-called "byte order mark".

- Code cleanup: improve format_plural usage, add some missing placeholder/check calls, and introduce API for <link> tags.

  a valid UTF-8 string, beginning and ending on a character boundary.

- Fix bug in decode_entities() with double-escaped entities.

- Patch #18828 by me, jbond and TDobes: moves the textarea hook for 'pre' between the title and the textarea. This makes it easier for simply textarea enhancements like quicktags to add a toolbar just above the textarea.

- Patch #19895 by Moshe: currently modules can inadvertently load all other modules during the bootstrap. this is easy to do by calling a node_load() or module_invoke_all(). this degrades performance for anonymous users when caching is enabled.  With this patch, the module writer will see an php error like "Call to undefined function: drupal_set_html_head()" if this is attempted. basically, unavailable functions are actually reported as unavailable.

- Patch #19590 by Moshe: lazy initialization of the theme system.  Improves
  performance of pages that don't need the theme system (such as RSS feeds)
  and makes it easier to set a custom theme.

- Tweak code style.