Added support for a custom-fields attribute for complex fields consisting of more than a single <input> element. Includes a placeholder-value attribute for data structures such as {}, or for other default but invalid values. When custom-fields is used, the entire transcluded content is inserted into the <ng-form> element.
Added documentation for new custom-fields and placeholder-value attributes. Documentation now shows live examples of custom fields.
Removed listInputConfig since it is no longer necessary or safe to modify the directive template.