Changes since DRUPAL-6--2-0-BETA2:
- #326281 by Starnox, Private file transfers sending text/plain MIME type.
- Dopry never comitted imagecache_update_5() to HEAD... playing catchup.
- #327919 by webernet: Update missing return value.
- #339840 by Gábor Hojtsy: Drupal 6 upgrade path broken due to cache.
- #338396 by chris.cohen: Rogue apostrophe in documentation.
- #336580 by drewish: "imagecache" directory left behind after uninstall.