Clean static_url management, add icons and clean settings.py and config.py.tmpl management with the static urls.

update language file, correct prefix in a template, enhance dialog during upload and remove useless language file.

Use django.contrib.staticfiles to manage static file. Reorganize static files in ldt folder. DO NOT forget to do command line ./manage.py collectstatic to gather static media into the web/static folder.

merge context_processors.py and enable upload cancel and remove temp file. Creation of a session temp folder for upload.