Make the modal expand to fit its contents

Make the modal expand to fit its contents in non-IE and IE8+ so that the
buttons are displayed on one line in all languages

Generally maintain the current behaviour in IE6/7, except that the 'no thanks' link is fixed, text is centered, and the second button is shifted down in some scenarios, rather than forcing the modal to scroll.

Bug: 61922
Change-Id: I6069e8e7139aabde432ff2dc8d5b902dbd17e2ae
Merge "Make the modal expand to fit its contents"