Implement dynamic locale lookup.

Allow dynamic locale lookup and rerendering when the `application.locale` value changes.

* Requires 1.9.0-beta.3.
* Removes `t` utility function (it was not usable standalone).

Closes #1.

@bcardarella - This is a fairly significant refactor. Please feel free to close this PR and reimplement using this as inspiration on how to get the rerendering to work.
I completely agree with you, we absolutely want a way to do this from JS as well as templates. The previous implementation didn't really support this (at least not without  a last arg that had `options.data.view`). We could implement an object that can be registered into the application (and is provided the `container` and `application` so it can find its values) and is then injected into things as `this.translate`.  Should be a simple implementation and still give us what we want...