add support for Visual Studio 2013

Add mkspec win32-msvc2013 and make VS 2013 known to configure and
qmake.

Change-Id: I6e63a4d679727a8a3f068f377956185996d72bce
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>
Show native file dialog on Windows XP Professional x64 Edition.

It claims to be WV_5_2 (WV_2003).

Task-number: QTBUG-32217

Change-Id: I0c277410acc9ac29710a3eee63bec9ced42e2767
Reviewed-by: Jonathan Liu <net147@gmail.com>
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>
Use case insensitive matching for hashes QFileSystemWatcher/Win.

Do not lower case file names to generate hash keys since
QString::toLower() converts some characters with context
which the Windows file system will not.

Task-number: QTBUG-31341

Change-Id: I285bfedef3c1ca9d59083229e61974dd378c72ae
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@digia.com>