Bug 10328 - Rename opaccolorstylesheet to OpacAdditionalStylesheet

Bug 10328 - Rename opaccolorstylesheet to OpacAdditionalStylesheet

Test plan (from comment #1)
1) Apply this patch
2) Run updatedatabase.pl
3) Verify the system pref OpacColorStyleSheet still works
   i.e. no change should be noted

Additionally, I changed the path to an other stylesheet and verified that it worked.

Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Works as described and no more occurences of opaccolorstylesheet were found.

Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>