Use magic geolocating Debian mirror

The previous mirror is quite slow, for people outside of China. This one should
auto-select a mirror that's geographically close to anyone using it.
Update to be compatible with current puppet

The current puppet-mysql module does not accept a config_hash parameter. Also,
use @ in templates to avoid deprecation warnings on more recent puppets.
Perform bootstrapping in Vagrant

Getting the system up shouldn't be any harder than "vagrant up". Configure
vagrant to run bootstrap.sh.
Merge pull request #1 from bitglue/master

Make installation simpler -- just "vagrant up"