Ensure that the Qt5Core library does not contain "QTMETADATA  ".

In the event the plugin loader encounters it due to some configuration
problem, it is otherwise detected as a plugin causing a crash
when trying to read the meta data.

Task-number: QTBUG-35970

Change-Id: I34182b3a61125e3b192dfd4b1dc03bd1e98c693e
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
Windows: Silence warning in QWindowsFileDialogHelper::selectFile().

The function is invoked from the QFileDialog constructor in
save file mode when passing a non-existing file.

Task-number: QTBUG-35703

Change-Id: I5c13efb9b6789404b28739f6ce88ed87b594b6e4
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>