Solve cyclic dependency of Units.qml
It imported Kirigami to check whether we are on mobile. Kirigami::Settings::isMobile checks whether QT_QUICK_CONTROLS_MOBILE is set. QtQuickControlsSettings always returns true on various mobile platforms (Q_OS_IOS, Q_OS_ANDROID, Q_OS_BLACKBERRY, Q_OS_QNX and Q_OS_WINRT) or checks QT_QUICK_CONTROLS_MOBILE.