Update YandexProvider
replace extension_exists() by function_exists() for mbstring
Merge pull request #266 from nicolas-grekas/mbstring-relax

replace extension_exists() by function_exists() for mbstring
fix maxmind binary provider encondig. Force utf8
Rename OpenStreetMaps => OpenStreetMap
Reintroduce OpenStreetMapsProvider for BC purpose

Closes #269
Prepare 2.3.0 release
Bump version to 2.3.1-dev
add fixEncoding method.
Merge pull request #268 from formapro-forks/maxmind-binary-fix-encoding

[1.7][maxmind] fix provider encondig. Force utf8.
Merge branch '1.7'
Merge pull request #265 from nicolas-grekas/patch-1

Update YandexProvider.php