Fix namespace usage such that all classes in shared/qml live in the
Qml namespace, and classes in QmlDesigner plugin in the QmlDesigner
namespace.
This should prevent any symbol clashes until we can finally get rid
of the file dublicates (e.g. QmlDocument).
QmlProject used LocalApplicationRunCOnfiguration, but didn't provide
e.g. an associated BuildConfiguration. Fix this by implementing it's
own QmlRunControlFactory, QmlRunControl.
Enables users to change which buildsteps get run per buildconfiguration.
Some further tweaks are probably necessary. This is a rather big
change, though it should work. :)
