Added module to support managing LXC containers

The new module will allow users to control LXC containers from ansible. The module was built for use in LXC >= 1.0 and implements most of what can be done using the various lxc clients with regards to running containers. This first module is geared only at managing LXC containers.

The module provides:
  * build containers
  * destroy containers
  * archive containers with the ability to compress the archive
  * info from a single container
  * start / stop / freeze /restart containers
  * run commands within containers
  * enable logging when creating a container
  * add / modify lxc config for a container
  * supports backends including LVM, directory, loop, btrfs

This PR is a continuation of the work that was done in PR: "https://github.com/ansible/ansible/pull/7825". In this PR the module has been refactored to remove the command pattern in favor of being declarative, I've removed fact gather parts of the module, and changed most of the shell commands to use the LXC python library where appropriate.