Not sure why we had the Bulgarian support but haven't recently updated
it (i.e. never with the model generation script, or so it seems),
especially with generic language models, allowing to have
UTF-8/Bulgarian support. Maybe I tested it some time ago and it was
getting bad results? Anyway now with all the recents updates on the
confidence computation, I get very good detection scores.
So adding support for UTF-8/Bulgarian and rebuilding other models too.
Also adding a test for ISO-8859-5/Bulgarian (we already had support, but
no test files).
The 2 new test files are text from page 'Мармоти' on Wikipedia in
Bulgarian language.
