Bug 9935 - Social icons missing in CSSR theme

Bug 9935 - Social icons missing in CSSR theme

When using CSSR theme, opac.css is missing css rules for social networks Facebook, LinkedIn ...

This patch copies css rules related to social netxork from prog theme to cssr theme.
Also copies social-sprite.png image.

Test plan :
- Set CSSR theme : syspref opacthemes=ccsr and opaccolorstylesheet=colors.css
- Set syspref SocialNetworks=Enable
- Go to a detail page at OPAC
=> check that social links are icons : Facebook, LinkedIn, Delicious, Send by email, Google Plus and Tweeter

Signed-off-by: Liz Rea <liz@catalyst.net.nz>
Social icons now showing, thanks!

Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>