Add header + title and Close button to forms

The following patch adds 2 options:

• Use the title of the link clicked as the title of the Modal dialog. Inserts a header bar to do that. If the title is not set in HTML, falls back to the link text. Requires Bootstrap 3.x
• If the html returns an .forms-actions class, which a lot of forms will, then a Close button is added that closes the Modal window without doing a server roundtrip. Requires Bootstrap 3.x