* Updates the precise image used to http://files.vagrantup.com/precise64.box
  * The new precise image requires a PPA for legacy node releases to be
    added for node 0.8.26 to be installed.
* Updates the node-gyp used to 0.12.2, some earlier versions have semver
  1.0.0 in the bundle from npm (package.json specifies '1'), this really
  old version of semver doesn't have the method 'gte' but node-gyp uses
  it.
* Adds some optional npm and apt caching config to Vagrantfile for
  properly configured vagrants