androiddeployqt: Add option to reinstall apk

Mainly for consistency with the old deployment method in Qt Creator,
androiddeployqt will uninstall any previously installed instances
of the application before installing it. This will remove any caches
or user data stored by the application. In many cases (most) it
would be more convenient to just overwrite the existing instance,
but keep all caches intact. This patch adds the --reinstall option,
symmetrical to --install. If enabled, the uninstall step will be
skipped.

[ChangeLog][androiddeployqt] Added option to install an APK without
uninstalling previous instances of same application.

Task-number: QTBUG-35845
Change-Id: I93bed4fefda6ed5295f333002a4958654b3f911c
Reviewed-by: Paul Olav Tvete <paul.tvete@digia.com>
windeployqt: Add missing "audio" plugins for QtMultimedia.

Task-number: QTBUG-39157
Change-Id: I88055eed7b430c14e1d1e13bdeee558a63763d8d
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>
Exclude qtdiag when QtGui is not available.

Task-number: QTBUG-39118
Change-Id: I54f6879ef58e5b7b7bc2c20840524f4af5433921
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>