Merge pull request #498 from rbs-maugier/master

[Add] Cross Selling
[UPDATE] Substitution variables for SEO metas
[UPDATE] Seo Substitutions works with functional page
[FIX] Metas of document SEO on document doesn't work
[UPDATE] getMetaVariable no longer has to create a new document
[UPDATE] remove some debug codes
Merge pull request #501 from renaudJennyRBS/seo

Seo Substitution variables for metas
[Fix]Cross-selling fixes