Adapt ConvertToTwo/ThreeCharCode methods for region code conversion.

Adapt ConvertToThreeCharCode to additionally check region codes.
Adapt ConvertToTwoCharCode to additionally check try xbmc specific language names.
[Python] Extend xbmc.getLangauge(...) to xbmc.getLangauge(int format = 0, bool region = false).
Allow to additionally retrieve the region of the language setting. The region is appended to the language.
For example:

Language-Region: Portuguese (Brazil)-Brazil
Language 2-Char-Region: pt-br
Language 3-Char-Region: por-bra