restructured to use subdirectories for each vm
first try with centos config
added credit + .gitignore generalized
renamed vagrant-scripts, box names

Makefile now has fewer .PHONY targets too.
reboots, adds vagrant user
working freebsd-10 build
fixed `clean`; was missing `vagrant box`
guest additions want kernel modules
run these commands as vagrant not root
no requiretty for vagrant
run make clean if updating
wipe /etc/sudoers + use sudo in vagrant setup
corrected bad formatting for sudoers
Merge branch 'feature/centos' into develop
centos support

- files reorganized
- Makefile made more generalized