Removed unnecessary comments.
Made caching of field errors being done only once per page load.
Rephrased a comment.
Made it possible to set a validation error message to appear in the top of a section output.
Added a change log item.
Removed some comments.
Added an example of field errors in the validation callback method in the meta box class.
- Changed the version number.
- Applied the changes to the minified version.
Updated the documentation files.