Inter-doc navigation + some minor changes [1/1]

- Inter-doc navigation (previous, next, up).
- Removed organization of index by barclamp.
- Fixed some minor issues.
- Add edit links to GitHub.


 .../app/assets/stylesheets/_common.sass            |    1 -
 crowbar_framework/app/assets/stylesheets/_nav.sass |   44 ++++++++++++++++++++
 crowbar_framework/app/assets/stylesheets/_toc.sass |    4 +-
 .../app/assets/stylesheets/application.sass        |    1 +
 .../app/controllers/docs_controller.rb             |   43 ++++++++++++++++---
 crowbar_framework/app/models/doc.rb                |   18 ++++----
 crowbar_framework/app/views/docs/_tree.html.haml   |    3 +-
 crowbar_framework/app/views/docs/index.html.haml   |   28 +++----------
 crowbar_framework/app/views/docs/show.html.haml    |   14 +++++++
 doc/devguide/documentation.md                      |   22 +++++-----
 10 files changed, 125 insertions(+), 53 deletions(-)

Crowbar-Pull-ID: 2cc39cf3de5eeeb81349f7ed27534f2335009f68

Crowbar-Release: development