added tips for vagrant
Update about-vagrant.md
Update about-vagrant.md
Update about-vagrant.md
Update about-vagrant.md

Correcting some spacing
Merge pull request #2 from tienyuan/master

Tips for using vagrant
Update README.md
Update README.md
Update Vagrantfile
Add instructions to use precise32 if necessary.
Update README.md
Update README.md
Update README.md
Actually use precise32. Not just say you're going to use it and then lie.
Faster ruby install.
Update readme.
Update README.md
Update README.md
Update README.md
Update README.md