feat: Remember user settings. Add progress icon for impatient users

VIPSWeb/static/css/vipsweb.css

cydiapomonella/locale/bg/LC_MESSAGES/django.po

cydiapomonella/locale/bs/LC_MESSAGES/django.po

cydiapomonella/locale/de/LC_MESSAGES/django.po

cydiapomonella/locale/fi/LC_MESSAGES/django.po

cydiapomonella/locale/nb/LC_MESSAGES/django.mo

cydiapomonella/locale/nb/LC_MESSAGES/django.po

cydiapomonella/locale/vi/LC_MESSAGES/django.po

cydiapomonella/locale/zh_Hans/LC_MESSAGES/django.po

cydiapomonella/static/js/cydiapomonella.js

cydiapomonella/templates/cydiapomonella/index.html

cydiapomonella/views.py