Minor UI tweaks and doc stubs [1/1]

title says it all


 .../app/controllers/snapshots_controller.rb        |    4 +-
 .../app/views/snapshots/show.html.haml             |   15 +++-----
 crowbar_framework/config/layercake.json            |   10 ++++-
 crowbar_framework/config/navigation.rb             |   20 ++++++----
 doc/devguide/devtool-build.md                      |    5 ++-
 doc/devguide/docker.md                             |   16 ++++++++
 doc/devguide/model.md                              |   15 ++------
 doc/devguide/model/attrib.md                       |    4 ++
 doc/devguide/model/barclamp.md                     |    3 ++
 doc/devguide/model/deployment.md                   |    3 ++
 doc/devguide/model/deployment_role.md              |   19 ++++++++++
 doc/devguide/model/group.md                        |    5 +++
 doc/devguide/model/jig.md                          |   10 +++++
 doc/devguide/model/node.md                         |   10 +++++
 doc/devguide/model/node_role.md                    |    3 ++
 doc/devguide/model/role.md                         |   39 ++++++++++++++++++++
 doc/devguide/model/snapshot.md                     |    3 ++
 doc/devguide/model/user.md                         |    3 ++
 18 files changed, 153 insertions(+), 34 deletions(-)

Crowbar-Pull-ID: c7561f8fbfa18abaaec23868319a2556de4c0e19

Crowbar-Release: development