Add functionality which will allow the user easily get security fixes for the plugins

Gerrit topic: https://review.openstack.org/#q,topic:bp/plugins-security-fixes-delivery,n,z

Addressed by: https://review.openstack.org/151256
    Security fixes for Fuel plugins

Addressed by: https://review.openstack.org/155705
    Use plugin ids instead of versions to enable/disable plugin

Addressed by: https://review.openstack.org/156571
    For plugins package version 2.0.0 use different data path

Addressed by: https://review.openstack.org/157854
    Add 2.0.0 plugins support

Addressed by: https://review.openstack.org/159523
    Fuel plugin builder generates rpm package instead of fp archives

Addressed by: https://review.openstack.org/161216
    Fix exception when plugin is being installed with --force

Addressed by: https://review.openstack.org/162123
    Add plugin package version 2.0.0

Addressed by: https://review.openstack.org/162128
    New plugin builder version should be 2.0.0

Addressed by: https://review.openstack.org/162992
    Add acceptance criteria for plugins updates

Gerrit topic: https://review.openstack.org/#q,topic:bug/1430327,n,z

Addressed by: https://review.openstack.org/163005
    Add optional fields for plugins table

Addressed by: https://review.openstack.org/165521
    Replaces self-writing subprocess wrappers with oslo_concurrency

Addressed by: https://review.openstack.org/165527
    Add python-oslo-concurrency as dependency for python-fuelclient