Revert "we cannot rely on session in helper methods (e.g. faults when using action mailer)"
Revert "we cannot rely on session in helper methods (e.g. faults when using action mailer)"

This reverts commit 5bfc9c82ba665584863ab47a08aae679455c3b4d.

coupling/spree_multi_currency,coupling/spree_multi_currency