In the corpus view (title, journals, terms), the navigation throught
buttons is not easy since, when user scroll down, buttons are not
visible (on top of the page).

The solution is fixing the navbar on top but there are some issue:
1) there is a conflict with jquery in the terms view so, we can not
click on titles or journals view any more
2) there is another conflict with bootstrap: click on username for
instance and we can not see the list items
3) aesthetic : the top navbar size is too large.