Major changes.  Don't install prereqs to system.  Clone ilastik-build-Linux instead.
Create hudson root directory.
Vagrantfile:
- Split provisioning script into two steps: root-level commands and user-level (user:vagrant) commands.
- Create separate script files for ilastik build and ilastik tests, which can be run manually via ssh.
- Renamed vm hostname to ilastikci
- Enable port forwarding from host:8022 -> ilastikci:22 for ssh (in case default 2222 -> 22 is not available on host)
- Configure VM with 4 CPUs.
Provision script:
- Install necessary X11 dependencies for Qt.
- Check for existing directories before cloning git repos.
- Set the BUILDEM_DIR variable in .bashrc
Updated Readme for new VM setup.
Specify master checkout when building ilastik.