check reports should fully support i18n.

[adamcin]

I think this should probably have the following acceptance criteria:

1. use standard ResourceBundle approach, with checklist libraries and opears providing i18n dictionaries to the framework
2. violations should probably support a simple format, varargs... construction, so that the format parameter can be used as a resourcebundle key for late binding in the case of serialized reports, and the serialized report super object should include any i18n keys applicable to the included violations, for all available locales.
3. resource bundle behavior should probably follow Sling i18n conventions
4. Execution interfaces should provide a option to specify a locale, as well as to infer the appropriate locale from the environment.

Edit: i18n and use of MessageFormat in oakpal checks is now standardized in the API with v2.0.0.

The next step should be to provide German translations for the standard checks and the DefaultErrorListener class: https://github.com/adamcin/oakpal/tree/master/core/src/main/resources/net/adamcin/oakpal/core