Forms, simplified, v2

• + Added ‘changed’ class to input_blocks
• + Added ‘confirm_unload’ class to make per-form abandonment warnings
• + Added __form_cancel_warning to forms.js
• + Added __form_abandon_change_warning to forms.js
• + Added a diskette icon to changed elements for better feedback response.
• ~ Clarified some comments

You can find it all here.