[Development] Qt Quick Controls 2 namespace change

[Frederik Gladhorn]

Since we created the repository originally as:
qt-labs/qtquickcontrols2, now is the time to rename it to qt/qtquickcontrols2 
since it's going to be a tech preview for Qt 5.6 and should be added to 
qt5.git with its final location.

So if your git pull stops working, just replace qt-labs with qt in your 
.git/config.
The change will hopefully happen very soon.

Cheers,
Frederik