[css] add the entypo font as available ressource (closes #2930356)
This provides a standard set of pictograms for use in CubicWeb and cubes.
To use a pictogram, the "cubicweb.pictograms.css"
must be explicitly loaded (using, e.g. view.add_css(...)).
cubicweb-web: embedded-javascript-library usr/share/cubicweb/cubes/shared/data/jquery.js