Minor CSS improvement for img.print-icon-margin

On line 18 in printlinks.css, there is the following line:

img.print-icon-margin {
   margin-right:4px;
}

This is a minor change, but I would recommend instead to make it as follows:

img.print-icon-margin {
   padding-right:4px;
}

The issue is due to how Internet Explorer renders margins versus padding. If a developer attempts to style the icons as a button, it will always be displayed in IE as broken (see attached pictures). However if padding is used, this problem doesn't occur.

The change from "margin" to "padding" has no effect in Firefox, Safari, or Opera.