Version update and a couple tweaks

I upped the version to 1.6.3 and made a couple tweaks: removed the redundant `-meteor` from the Atmosphere name, so the smart.json name is now just `i18next`, and used the non-minified version by default (because meteor deploy always minifies for free).

If you merge this PR, could you also do another `mrt release .` so Atmosphere gets updated?

Thanks!