The main feature for this version upgrade is the use of the instruction
emulator (IEM) to speed up execution and less often the slow recompiler.
issue #2059
Add option to load the initial overlay*.vdi from disk, but keep the changes
in a ram_fs.
Used with AHCI model for vbox_auto_win7. Currently we have no way to tell
rump_fs to unmount and write back data to disk before resetting the machine.
This commit enables the VirtualBox graphics adapter, provides guest mouse
pointer integration with Nitpicker using the 'vbox_pointer' application
and enhances the VirtualBox run scripts with the configuration of
Nitpicker, input merger and network driver.
Fixes#1474
