Bug 10404: tweak style of staff client previous/next links

Bug 10404: tweak style of staff client previous/next links

This patch slightly modifies the styles of the previous/next links in a
way that I think is simpler and clearer.

To test, apply the patch and clear your browser cache if necessary.
Perform a search in the staff client, click any result, and look at the
prevous/next links.

Signed-off-by: Magnus Enger <magnus@enger.priv.no>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>