- renderChildren() does not cast result to string anymore in AbstractViewHelper
- Added ViewHelperException. If this is thrown while rendering a view helper, the corresponding ViewHelperNode catches the Exception and can react appropriately depending on the excecution context (Currently it simply returns the error message).
- Rewrote Format-ViewHelpers to use tag contents as their main input as discussed in the mailing lists
- TextareaViewHelper: attributes rows & columns are required now