WIP: Add a Vagrantfile

Vagrant (https://www.vagrantup.com/) allows easy, reproducible
development environment setups by specifying minimal virtual machine
setups.

Here, we add a simple and easy Vagrant configuration to be able to
configure and build VirtualBox.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
WIP: Allow compiling the Linux module on case-insensitive filesystems

TODO: VBoxNetFlt.o, VBoxNetAdp.o

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>