- Upgrade to fluent 0.4.1.

  - Removed caching in `Localized`'s state until we know more about performance
    bottlenecks.

  - Added the `withLocalization` HOC.

    It may be used to connect a component with a Localization. It injects the
    `getString` prop.

  - The compat build is now transpiled using rollup-plugin-babel.

    This ensures that the "use strict" pragma is scoped to the UMD wrapper.  It
    also correctly parses the top-level "this" keyword (which the previous
    setup turned into "undefined").