[uicfg] uicfg.py moves from web/ to web/views/ (prepares #2406609)
We are about to make uicfg selectable. Registrable / selectable views
and helpers live in web/views. Hence the move.
Backward compat is put in place. However CubicWeb imports of uicfg are
updated to the new location.
fontcolor = 'black'
bgcolor = '#FFFFFF'
stylesheets = sheet['stylesheets'] + ['%s/mycube.css' % datadir_url]