SVGHMI: add static file serving feature.
Added two buttons to add and remove files.
Files are stored in project inside a directory named "static",
itself located in svghmi CTN instance files. Exemple :
exemples/svghmi_csv_json_img_table/svghmi_0@svghmi/static/
Files are transfered as "extra_files", but with a prefix
added to their name to avoid conflics.
# those files are used in runtime
# licensed according to LGPL, see COPYING.runtime
images/icostop24.png
images/icoplay24.png
images/brz.png
util/__init__.py
util/paths.py
runtime/WampClient.py
runtime/PLCObject.py
runtime/NevowServer.py
runtime/webinterface.js
runtime/webinterface.css
runtime/__init__.py
runtime/ServicePublisher.py
runtime/typemapping.py
runtime/loglevels.py
Beremiz_service.py
version.py