Add basic support for optional region-codes #13
Description
While I don't want to change the way this extension manages and uses languages in the backend (2-character ISO 639-1-codes) I'm planning to add some basic support for optional region-codes in the frontend. All methods explained in the language detection stack (except the fallback language) should be able to include an optional region-code that's accepted, understood and processed by the extension - meaning the extension will extract the 2-character language-code, use that like before and simply add the optional region-code to the parameter pool for individual usage in the templates.
An example of different url-structures that are planned to be supported:
domain.com/page/?language=endomain.com/page/?language=en®ion=usdomain.com/en/page/domain.com/en-us/page/en.domain.com/page/en-us.domain.com/page/