Implement Consistent Qt3D Naming

Project Naming Now Set to be Qt3D

This bug is to capture all items required for ensuring consistent and correct naming of all sites, properties, binaries, repos, documentation items and communications for the Qt3D project and its deliverables.

Sub-tasks should be specified for the parts of the work required.

• qt/3d repo creation and code migration - this should probably be the same thing as the "master" and contain our qt5 support going forward
• switch to upstream internal qt5 projects pulling from this new repo instead of the qml2 branch
• rename quick3d -> qt3d in all documentation
• ensure all library names, plugin names, import statements and other code artifacts are correct
• update build scripts so that packages for harmattan, windows and other platforms use the correct naming
• create blog post announcement and advise community of change