Add GollumWiki#empty? method
Consistent naming to make difference between clicking on profile pic and profile settings clear.
Skip rather than fail empty wikis during backup
Merge branch 'consistent-naming-of-user-and-profile-page' of /home/git/repositories/gitlab/gitlabhq
Merge branch 'wiki_backup' of /home/git/repositories/gitlab/gitlabhq
On-the-fly static rendering of IPython notebooks

If enabled (via the ipython_notebook.render configuration setting),
visiting the blob view on any .ipynb file triggers a call to IPython
nbconvert and the result is included in an iframe. IPython (>= 1.0)
must be installed on the server.

Note that this is a very ad-hoc patch. For example, rendered notebooks
are not cached meaning that performance may be suboptimal.