feature-DialogImprovements

Adds the following improvements to the QDialog class.

1) Confirmation button that will put up a browser confirmation message before the click is recorded.
2) The ability to stylize buttons as default or left/right
3) Fixes problems related to the default button. This now correctly traps the return key and sends it to the default button event when there is no field on the dialog. Before it would send it to the form, which would fire the default button on the underlying form.
4) buttonId is not longer required. If not provided, the text of the button becomes the Id. Also, button Ids are not the css id of the button, so you don't need to worry about making them unique across all dialogs in a form. You can still provide a css id through the new options array for the button.
5) Lets you use Themeroller styling for Error and Highlight state.

Includes changes to the examples page to highlight the differences.

Sorry that its not easy to review. Not sure why the diffs are not very clean.