Compiling for retina

[BobbyMcFerrin]

Now that VirtualBox supports unscaled HiDPI mode I am moving my linux installation from my current dual-boot setup. I managed to get almost everything working, except a couple things - horizontal scrolling, and cmd-(shift)-h (which I use extensively in my window manager keybindings (herbstluftwm)).

I managed to compile VirtualBox with this patch, and that indeed allowed me to use cmd-h, however it also completely messed up the GUI and the virtual machine rendering. Random chunks of the display would intersect other chunks and it was unusable. Is this because I was compiling from HEAD or is there something special I need to do to get retina support?