Converted msrp_rwd.js to vanilla javascript

[fballiano]

This is a small conversion from prototypejs to vanilla javascript, it affects a minor file: msrp_rwd.js

Manual testing scenarios

1. enable RWD theme
2. enable MSRP in configuration -> sales -> sales -> Minimum Advertised Price
3. also enable "Apply MAP (Default Value)"
4. flush caches
5. go to frontend, browse do a product page
6. price is hidden by default, if you click on these 2 links:

an overlay popup is shown with some info

[elidrissidev]

Since helpBox and bodyNode are now an HTMLElement, the calls below to add and remove a class should be changed to element.classList.add() and element.classList.remove() respectively.

magento-lts/skin/frontend/rwd/default/js/msrp_rwd.js

Lines 22 to 31 in d3dcc76

	helpBox.removeClassName('map-popup-right');
	helpBox.removeClassName('map-popup-left');
	if (Element.getWidth(bodyNode) < event.pageX + (Element.getWidth(helpBox) / 2)) {
	helpBox.addClassName('map-popup-left');
	} else if (event.pageX - (Element.getWidth(helpBox) / 2) < 0) {
	helpBox.addClassName('map-popup-right');
	}
	} else {
	parent(event);
	}

[fballiano]

I tested the helpbox when I did the PR and it was working, I'm checkin it anyway

[fballiano]

right, removeClassName and addClassName are from prototypejs, they still work but I'll change them in a few secs

[elidrissidev]

Ahh ok, so prototype is adding those methods to native HTMLElements too.