Remove Mesa 10.3.7 whose LLVMPipe is not compatible with OE Rocko's new LLVM version. Prepare a switch from VBox+VBoxGuestAdditions to QEMU+VirGL3D

packagegroup-qt5-toolchain-target: Don't depend on qtquick1, qtwebkit and qtquickcontrols2 but depend on most nemo-qml-plugins, qtvirtualkeyboard, mapplauncherd, qtmpris, glibmm and qml-asteroid so that the SDK can actually be used to build Asteroid apps

libhybris: Use the newer version provided by meta-smartphone rocko and don't use the wifi module which breaks every build

Adds an old-kernel-gcc-hdrs bbclass to provide the include/linux/compiler-gccX.h headers needed by 3.10 kernels when built with newer GCC versions (5, 6 and now 7 with the upgrade to rocko)

dbus: Install an apropriate session bus configuration for geoclue-hybris (which has a setuid bit and owns a session service as root)