Basic port of marble-touch from QtQuick 1 to QtQuick 2

There are lots of rough edges left, but it starts again and allows some basic
interaction. The two main changes are porting MarbleDeclarativeWidget to
QtQuick 2 (use MarbleQuickItem instead of a QGraphicsProxyWidget and
MarbleWidget) and replacing the obsolete harmattan / plasma qt components
with QtQuick Components.