Update built-in documentation to match menu changes

We renamed and relocated most of the administration related menu items but Drupal's built-in documentation has not been updated accordingly.

$ grep -lr "site configuration" *
INSTALL
modules/forum.module
modules/comment.module
modules/drupal.module
modules/statistics.module
modules/story.module
modules/system.module

$ grep -lr "block management" *
modules/block.module
modules/cloud.module
modules/import.module

$ grep -lr "user management" *
INSTALL
modules/bloggerapi.module
modules/comment.module
modules/system.module

$ grep -lr "comment management" *
modules/comment.module

$ grep -lr "content syndication" *
modules/cloud.module