Refactored get_site_id into an utility function.
get_site_id was implemented twice, once in templatetags/cms_tags as get_site
and once in utils/i18n.py as get_site_id.
This is a prerequisite for multisite installations.
Merge branch 'develop' into multisites
Added missing ValueError to exception
Refactored get_site_id from cms.utils.i18n -> cms.utils.conf
Merge pull request #2339 from jrief/multisites

Refactored get_site_id into an utility function.