engine()->rootContext() will give a different result to
rootContext() when using a shared engine.
One being in the right context, the other being the context of the
shared engine. Using the latter means two panels end up sharing the same
object which leads to some interesting results and QML crashes in
QV4::QObjectWrapper::wrap when one gets deleted.
I've tested against 356545, but I think it's the cause of a lot of the
mystery QML bugs we couldn't figure out.
BUG: 356545
BUG: 355885
BUG: 356916
REVIEW: 126491
this because due to Qt xcb implementation the actual flags gets
set only after a while after the window is actually visible.
kwin has actually time to move the window since is not a dock yet,
at the moment there is no solution besides moving it back
BUG:339614
when the panel mode is autohide, the visibility mode has to be
altered when the controller is open, or the panel will go invisible
also when the mode is windowcancover is better to alter, or the panel may disappear
as well.