Fix a network configuration issue of Fedora [GH-1997]

Support Predictable Network Interface Names (PNIN).

I tested on Fedora19 and Fedora20, both vms' private/public network worked fine.

- Fedora19 https://dl.dropboxusercontent.com/u/86066173/fedora-19.box
- Fedora20 https://vagrantcloud.com/chef/fedora-20
- setting is https://github.com/mitchellh/vagrant/issues/1997#issuecomment-37328822

Fedora's udevd renames original nic name to predictable nic name (e.g "eth0" to "p7p1"). 
http://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames/

This patch can get original nic name using biosdevname command, then set each network interface's script defined in vagrant file.