It was added yesterday for testing purposes. We're not sure if we're going to keep it or not; we'll see. It simply reveals if a datatype has multiple inputs or not. If a datatype has several inputs (like for example the image/user/author/selection/etc. datatypes), the inputs will be grouped and rendered slightly differently than before. Reason: gives a more user friendly interface and even more correct markup than we've had before. Screenshot here:
http://home.atc.no/~allman/datatypes.png
(notice the grouping of the input fields, checkboxes, buttons and etc. that belong to the author attribute)
You don't have to have this file unless you want better rendering of certain datatypes which have multiple inputs. We're working on some function calls which will make the initial idea (and some additional stuff) come true in an elegant way. The ini file + the necessary template code (see design/admin/content/edit_attributes.tpl) were added for testing purposes (both will probably change within the next days). Stay tuned.
