This issue fixes a bug that happens when a SFC has a <i18n> block aswell as a i18n configuration in the Vue Component options.
Previously, the i18n configuration from the Vue Component options would be overridden by the <i18n> block; Using this new behaviour, the <i18n> block and the i18n configuration from the Vue Component options are merged.
This also helps to provide mixin support, since now a consumer of this library can have a SFC as a parent component, which uses a Vue mixin, and using a custom vue optionMergeStrategy, full mixin support can be achieved from consumer side.