LXC and other host packages are installed inside containers

[Bjoern]

I have noticed that lxc, lxc-dev or debootstrap is installed inside the repo container.
We should check if we intend to use these packages in the future, if not we should remove them.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/289510

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/291933

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/291933
Committed: https://git.openstack.org/cgit/openstack/openstack-ansible-repo_build/commit/?id=fcd7e3d2acc50be1488855d79c0e194ce3e31e70
Submitter: Jenkins
Branch: master

commit fcd7e3d2acc50be1488855d79c0e194ce3e31e70
Author: Jimmy McCrory <email address hidden>
Date: Fri Mar 11 14:15:14 2016 -0800

    Install packages necessary to build Python wheels

    Include additional tasks to install apt packages necessary to build
    Python wheels required by OpenStack-Ansible.

    These packages were formerly installed by the repo_server role.

    Since lxc-dev is installed as a requirement for building lxc-python2, an
    lxc-net override file is dropped to prevent the lxcbr0 bridge and
    dnsmasq service from starting and potentially causing issues.

    Change-Id: I03d5c061ec506a9dc142ff55a50fb3ecb18c238f
    Partial-Bug: #1550418

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/289510
Committed: https://git.openstack.org/cgit/openstack/openstack-ansible-repo_server/commit/?id=b0836d3b22feab4bafd186a626fa03b1a93b41ad
Submitter: Jenkins
Branch: master

commit b0836d3b22feab4bafd186a626fa03b1a93b41ad
Author: Jimmy McCrory <email address hidden>
Date: Mon Mar 7 08:34:53 2016 -0800

    Trim apt package list

    Limit repo_apt_packages to a more minimally viable list of requirements
    for deploying Nginx servers and syncing files between them.

    Change-Id: I677c78473b7f0442f8c334cd59b8c676973f4535
    Depends-On: I03d5c061ec506a9dc142ff55a50fb3ecb18c238f
    Closes-Bug: #1550418