Convert from QString unicode from/to the OS-dependent locale as used by boost::filesystem::path as needed.
This should make data directories with special characters in Windows work.
Test builds (windows) can be found here: https://download.visucore.com/bitcoin/bitcoin-2014_03_qt_unicode_path_v3.zip Signature: https://download.visucore.com/bitcoin/bitcoin-2014_03_qt_unicode_path_v3.zip.sig