Explicitly fix yum to a release for the install.
Don't turn on the second interface.

Implemented originally due to a bug in Vagrant 1.4

Partially reverts df87be2d92a340141aeec26dc88bfc4429e50c08
CentOS doesn't like it when this file is empty
Set this up in %post instead of ks params

Lends possibilities for the version number to be listed
once somewhere.
Turn off more services until next 'first boot'