Add altering rows colors to (cataloging) manage authorities interface

To make it easier to use the (cataloging) manage authorities interface I added a tiny bit of CSS to have alternating row colors. The "height: 1.5em" part is needed because the enclosing authEntry div ends up with a height of zero because its children containers are all floating. Turns out this zero height behavior is not a bug, but a natural side affect of floating the div's children.

Signed-off-by: Yamil Suarez <yamil@yamil.com>
Signed-off-by: Lebbeous Fogle-Weekley <lebbeous@esilibrary.com>