salt.modules.lxc: fix warning

/cc @mgwilliams
bypass any test for lxc virtual
LXC managment improvments

- Add functions to the module
- Introduce a new state module to manage lxc containers via salt states
salt.modules.lxc: add ip & size to infos
salt.modules.lxc: fix lxcconf gen. and add extra infos to list
salt.modules.lxc: add dns servers managment
salt.states.lxc: pep8
lxc: Separate more concerns and remove out of scope functions
lxc: vgname does not apply to clone
Merge pull request #10898 from makinacorpus/lxc

Lxc