- we need the basePath concept for the main i18n class so we can pull it out into a module
- we already had this in the themeI18n class, so I just had to move it up
- also I added a default of __dirname, so we don't have to declare this constantly in the tests
- final preparation for moving i18n out of Ghost core
- logging is passed in via DI
- theme i18n needs a config value, but no need to pass all of config for one parameter, a better pattern is to pass the one value needed
- preparation for using DI instead of requires, so we can move this out of Ghost
- have done this for both the main i18n and theme i18n file
- refactored the constructor
