Widgets: Set qt_button_down for each press.

Do not rely on release events.

Task-number: QTBUG-31333
Change-Id: I09a056fed8892715c04ca78a42ae191e5a9a3b42
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>
Use BSD licensing for QtOpenGLExtensions instead of LGPL

BSD licensing should be used for QtOpenGLExtensions instead of LGPL as
it is a static library that is linked into applications. Using LGPL
would impose additional requirements for application developers to
provide object files to end users to be able to relink the application
with a modified or updated QtOpenGLExtensions static library.

Task-number: QTBUG-29918
Change-Id: I0bb80f8ba5158be0a71fe4c5e1c37787ce21337d
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
Mac: Ensure that C++11 is always used when linking against a static Qt build

If Qt was built with C++11, it links to libc++, and we need all projects
that use Qt to link against the same library.

Technically, we could do QMAKE_LFLAGS += -stdlib=libc++, but that hasn't
been tested enough without also enabling C++11, so we keep the
relationship between the two for now.

Change-Id: Ic628bcbade60cc82f93707f372c2119c24d9dc8a
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Reviewed-by: Liang Qi <liang.qi@digia.com>
Fix QDir::mkpath failing for drive paths on Windows

This fixes a regression introduced in 3e2cd8ef6f1ce4f467. We shouldn't try
to call mkdir for just a drive letter.

Task-number: QTBUG-31862

Change-Id: I56035857aec03f9f1cceef62e82f372486b7737b
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>
Reviewed-by: Kai Koehne <kai.koehne@digia.com>