Bug 22772: Menu link hover color incorrect in OPAC language choosers

Bug 22772: Menu link hover color incorrect in OPAC language choosers

This patch makes a few corrections to OPAC CSS to fix colors in the
language menus.

To test, apply the patch and rebuild the OPAC CSS.

- Enable multiple languages in the OPAC, including more than one
  language "variation" (fr-FR, fr-CA).
- Set the OpacLangSelectorMode preference to "both."
- In the OPAC, test the language menu in both the header and footer.
  When you hover over the sub-menu items the background should be green
  and the text color white.
- Perform the same test in the self checkout and self checkin
  interfaces.

Signed-off-by: Claire Gravely <claire.gravely@bsz-bw.de>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>