C++: handle case-insensitive file names in the WorkingCopy

... by keying on Utils::FileName

Task-number: QTCREATORBUG-12390
Change-Id: Ia1a59d2e422b4f92300ac6a8e0e52dd7456a6e70
Reviewed-by: Eike Ziller <eike.ziller@theqtcompany.com>
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@theqtcompany.com>

src/libs/utils/fileutils.cpp

@@ -721,6 +721,11 @@ FileName &FileName::appendString(QChar str)
     return *this;
 }
 
+QTextStream &operator<<(QTextStream &s, const FileName &fn)
+{
+    return s << fn.toString();
+}
+
 static bool isFileDrop(const QMimeData *d, QList<FileDropSupport::FileSpec> *files = 0)
 {
     // internal drop