Use the new build env on Travis

more ram and cpu, improve network and vm boot times

http://docs.travis-ci.com/user/workers/container-based-infrastructure/

more docs coming soon
Minor tweaks.
Update docs etc to point to spree-contrib.
Point to correct branch for 2-4-stable.
Translate submitted_on correctly
Translate approval_status
tr: Onay -> Onay Durumu
pt, pt-BR: approval_status -> Estado de aprovação by @hernanilr
sv, es: approval_status corrected by @futhr
fr: correct approval_status by @bricesanchez
Correct Romanian approval_status
Remove 'noindex' from rel attr

Closes #125