Changed Device name to fix private_network bug

If you try and start fedora with a :private_network, it will fail saying the 'p7p1 device doesn't exist'. Fixed with changing device to eth.
--provider on box add supports any format of that provider
VBoxManage customizations can run at different events [GH-1247]
Config validation error if :id in pre-import VBoxManage
Discover and set SSH_AUTH_SOCK on sudo with forward agent [GH-1307]
VirtualBox no longer removes network interfaces [GH-1324]
Mount NFS with UDP protocol by default [GH-1706]
Replace '\' with '/' on synced folders on Windows
Unused config objects are finalized properly [GH-1877]
Merge pull request #1738 from drogerschariot/master

Private Network bugfix in Fedora by switching p7p to eth
Update CHANGELOG