* add the branding in translation mode
* change javascript to add the lang in the context (automatically removed in the rte => allow to create record and edit when use an other default language of en_US)
* avoid double saved
The stdlib version of the json library is more recent than the 3.5.3
version we are pinning in `requirements.txt`
There is no reason to use it.
Closes#6940
Replace deprecate controllers like /web/binary/image, /web/binary/saveas...
Use ETag for all content with 'unique' option to cache the content if the content is never changed.