bulma (base): loading screen: when the `loading_screen` variable is set before extending `base/base.html`, a loading modal is shown (and must be removed via JavaScript). This avoids the user to try to use an interface which is not reactive or working normally because JS is not fully loaded yet.

include MANIFEST.in sat_templates/VERSION
global-include *.py
global-include *.html *.xml
global-include *.css *.js
global-include *.woff *.woff2
global-include *.ini
global-include *.po *.mo
global-include *.txt
global-include CHANGELOG COPYING* INSTALL README*
global-exclude *.un~