Drop the current displayed text

We will handle contrast differently

To translate all texts, we added more promises and queues to make sure everything works as expected

Clean up and Change all gadget's CSS rules to be prefixed by  `div[data-gadget-url$="gadget_document_scanner.html"]`

The http response should return a 200 response in case of success. The response body may contain a local reference of the uploaded image

Request body should contain the image data and the active process relative url (depending on which erp5 context the script is called)

make jslint happy

* change the `extra renderjs` parameters list to pass a Python script to call when a new image is cropped.
* change the gadget to use jio.util.ajax with the script full url (provided by the server)

Change the gadget checkValidity method to return false when:
- no thumbnail has been generated
- a thumbnail upload is in failed state

The default value is a JSON containing 2 keys:
- the relative_url of an active process
- the list of active process image content to aggregate
By default, when the field is rendered for the first time, this tales expression is evaluated and a new active process is created at that point.
So, default json is like: {active_process: 'portal_activities/1234', image_list: []}
* store the active_process relative_url in the gadget state in the render method
* store the image_list in the gadget state in the render_method
* change getContent method to send a json build from the active_process and image_list state

If device_id is propagated to onStateChange, it means we have a new value. Then, check if we have this property is enough to switch

XXX
Allow to show previously uploaded image.
Allow to delete or retry uploading.

Form submittion only send the active process informations.

Stop relying of CSS hide/show attributes.
Instead, only put needed elements in the DOM.

There are 2 shemes for VIRTUAL_URL_PARTS:
- 2-tuple with SERVER_URL and subpath
- 3-tuple with SERVER_URL, vh path and subpath
This code only supported the 2-tuple version, add support for the 3-tuple
version.

Make ERP5Type.Base and ERP5.ERP5Site inherit from it.

Allows Base to consistently override methods which are also overridden in
CMF where CMF implementation does not propagate the call to other
superclasses (ex: __before_publishing_traverse__ as of CMFCore-2.2.10).
Also allows simplifying several inheritance fixups.
Also, use super() instead of explicit resolution to Base.

Also: testBusinessTemplate: drop dead monkey-patch.
_getCopy is called during BusinessTemplate installation, but not the one
on this class. Which prevents reordering class inheritance between
SimpleItem and copy support classes.
So this is dead code which is not even explaining what it is trying to do
(ex: what document should it really not be called on ? what effect of this
method is undesired ? why is the method attached to this class ? why is
the cleanup restoring the original method, when this class does not have
this method to begin with but it merely gets it from its superclasses
which are re-inherited from by documents hence overriding it anyway ?,
and it is getting in the way of reordering class inheritance so it goes
away.

Also: ERP5Type.patches.CMFBTreeFolder: Fold patch onto ERP5Type.Core.Folder.
All ERP5UI-visible (hence needing to call allowedContentTypes) BTReeFolder2
instances should already inherit ERP5Type.Core.Folder, removing the need
for this monkey-patch.