Fix: I18N doesn't work on Windows

Qt expects QM files is placed in case-insensitive file system
on Windows.  QIFW loads QM files from QRC and QRC is case-sensitive
file system.

Change-Id: I1965ec2344e2db6315e84a25ebb3098b11f611c6
Reviewed-by: Niels Weber <niels.weber@digia.com>
Reviewed-by: Karsten Heimrich <karsten.heimrich@digia.com>