more improvements to build.sh, remove some external dependencies
more improvements to build.sh, remove some external dependencies

mfkenney/vagrant-debian,tiwilliam/vagrant-debian,jakubvokoun/vagrant-debian,scottalan/vagrant-ubuntu-precise-64,scottalan/vagrant-ubuntu-precise-64,cal/vagrant-ubuntu-precise-64,cal/vagrant-ubuntu-precise-64,charnad/vagrant-ubuntu-box-builder